When , ice changes into water. A. to heat B. heating C. heated D. they are heated 题目和参考答案——青夏教育精英家教网—

Have you ever noticed the colour of the water in a river or stream after a heavy rainfall? What do you think caused this change in colour? It is soil that has been washed into the river from the riverbank or from t}le nearby fields．

Components of Soft

Soil is made up of a number of layers(层)，each having its own distinctive colour and texture．The upper layer is known as the litter．It acts like a blanket．limiting temperature changes and reducing water loss．The topsoil layer is made up of small particles of rock mixed with rotten plant and animal matter called humus(腐殖质)，which is black and gives the topsoil its dark colour．This layer is usually rich in nutrients，oxygen，and water．Below the topsoil is the subsoil，a layer that contains more stones mixed with only small amounts of organic matter．This layer is lighter in colour because of the lack of humus．Beneath the soil lies a layer of bedrock．

Soil forms from the bottom up．Over time bedrock is attacked by rain, wind，frost, and snow．It is gradually broken down into smaller particles in a process called weathering．Plants begin to grow，and rotten materials enrich the topsoil．Most of the soil in Eastern Canada．for example．Was formed from weathered rock that was exposed when the ice disappeared l2．000 years ag0．

Water Beneath the Soil

Surface water collects and flows above the ground in lakes．ponds．and rivers．Once in the soil or rock，it is called groundwater．Gravity pulls groundwater through the soil in a process called percolation(渗透)．Eventually the water reaches a layer called the water table．Under this is bedrock through which water cannot percolate．

As water percolates downward，it dissolves organic matter and minerals from the soil and carries them to deeper layers．This causes a serious problem because plants require these nutrients for growth.

Soil pH

Soil can be acidic．neutral．or basic．The pH of the soil is determined by the nature of the rock

from which it was formed．and by the nature of t}le plants that grow and rot in it．

The acidity of rain and snow can lower the pH of the groundwater that enters the soil．By burning fossil fuels such as coal，oil and gasoline，humans have been contributing to higher levels of acidity in many soils．When fossil fuels are burned．gases are released into the air and then fall back to earth as acid rain．Acid soil increases出e problem of carrying nutrients to lower soil levels．As nutrients are removed，soil is less fertile．Plants grow more slowly in acidic soil，and also become easily attacked by diseases．

67．The layer of soil that provides necessary nutrients for plant growth is called．

A．1itter B．topsoil C．humus D．subsoil

68．According to the text．which of the following is NOT true?

A．Soil forms from weathered rock on the earth surface．

B．The deeper layer of soil is darker in colour than t}le surface soil．

C．Air pollution is partially responsible for acid soil．

D．Groundwater tends to carry away nutrients for plant growth．

69．We can infer from the passage that the water table lies ．

A．between the topsoil layer and the subsoil layer

B．in the subsoil layer above bedrock

C．between the subsoil layer and bedrock

D．in the bedrock layer beneath the subsoil

70．The underlined word “dissolve” is used to express the idea that organic matter and minerals from soil are ．

A．rushed away into the river

B．cleaned and purified by water

C．destroyed and carried away by water

D．mixed with water and become part of it

Have you ever noticed the colour of the water in a river or stream after a heavy rainfall? What do you think caused this change in colour? It is soil that has been washed into the river from the riverbank or from t}le nearby fields．
Components of Soft
Soil is made up of a number of layers（层），each having its own distinctive colour and texture．The upper layer is known as the litter．It acts like a blanket．limiting temperature changes and reducing water loss．The topsoil layer is made up of small particles of rock mixed with rotten plant and animal matter called humus（腐殖质），which is black and gives the topsoil its dark colour．This layer is usually rich in nutrients，oxygen，and water．Below the topsoil is the subsoil，a layer that contains more stones mixed with only small amounts of organic matter．This layer is lighter in colour because of the lack of humus．Beneath the soil lies a layer of bedrock．
Soil forms from the bottom up．Over time bedrock is attacked by rain, wind，frost, and snow．It is gradually broken down into smaller particles in a process called weathering．Plants begin to grow，and rotten materials enrich the topsoil．Most of the soil in Eastern Canada．for example．Was formed from weathered rock that was exposed when the ice disappeared l2．000 years ag0．
Water Beneath the Soil
Surface water collects and flows above the ground in lakes．ponds．and rivers．Once in the soil or rock，it is called groundwater．Gravity pulls groundwater through the soil in a process called percolation（渗透）．Eventually the water reaches a layer called the water table．Under this is bedrock through which water cannot percolate．
As water percolates downward，it dissolves organic matter and minerals from the soil and carries them to deeper layers．This causes a serious problem because plants require these nutrients for growth.
Soil pH
Soil can be acidic．neutral．or basic．The pH of the soil is determined by the nature of the rock
from which it was formed．and by the nature of t}le plants that grow and rot in it．
The acidity of rain and snow can lower the pH of the groundwater that enters the soil．By burning fossil fuels such as coal，oil and gasoline，humans have been contributing to higher levels of acidity in many soils．When fossil fuels are burned．gases are released into the air and then fall back to earth as acid rain．Acid soil increases出e problem of carrying nutrients to lower soil levels．As nutrients are removed，soil is less fertile．Plants grow more slowly in acidic soil，and also become easily attacked by diseases．
【小题1】The layer of soil that provides necessary nutrients for plant growth is called．

【小题2】According to the text．which of the following is NOT true?

A．Soil forms from weathered rock on the earth surface．

B．The deeper layer of soil is darker in colour than t}le surface soil．

C．Air pollution is partially responsible for acid soil．

D．Groundwater tends to carry away nutrients for plant growth．

【小题3】We can infer from the passage that the water table lies ．

A．between the topsoil layer and the subsoil layer

B．in the subsoil layer above bedrock

C．between the subsoil layer and bedrock

D．in the bedrock layer beneath the subsoil

【小题4】The underlined word “dissolve” is used to express the idea that organic matter and minerals from soil are ．

A．rushed away into the river

B．cleaned and purified by water

C．destroyed and carried away by water

D．mixed with water and become part of it

What do you want to be when you grow up? A teacher? A doctor? How about an ice-cream taster?

Yes, there really is a job where you can get paid to taste ice cream. Just ask John Harrison an “Official Taste Tester” for the past 21 years. Testing helps manufacturers (制造商) to be sure of a product’s quality. During his career Harrison has been responsible for approving large quantities of the sweet ice cream—as well as for developing over 75 flavors (口味).

Some people think that it would be easy to do this job; after all, you just have to like ice cream, right? No—there’s more to the job than that, says Harrison, who has a degree in chemistry. He points out that a dairy or food-science degree would be very useful to someone wanting a career in this “cool” field.

In a typical morning on the job, Harrison tastes and assesses 60 ice cream samples. He lets the ice cream warm up to about 12℉. Harrison explains: “You get more flavor from warmer ice cream, which is why some kids like to stir (搅拌) it, creating ice-cream soup.”

While the ice cream warms up, Harrison looks over the samples and grades each one its appearance. “Tasting begins with the eyes,” he explains. He checks to see if the ice cream is attractive and asks himself, “Dose the product have the color expected from that flavor?” Next it’s time to taste!

Continuing to think up new ideas, try out new flavors, and test samples from so many kinds of ice cream each day keeps Harrison busy but happy---working at one cool job.

1. What is John Harrison’s job?

A. An official. B. An ice-cream taster.

C. A chemist. D. An ice-cream manufacturer.

2.According to John Harrison, to be qualified（合格的） in the “cool field”, it is helpful to ________.

A. keep a diary of work

B. have a degree in related subjects

C. have new ideas every day

D. find out new flavor each day

3. What does Harrison do first when testing ice cream?

A. He stirs the ice cream.

B. He examines the color of the ice cream.

C. He tastes the flavor of the ice cream.

D. He lets the ice cream warm up.

4.Which of the following is probably the best title of the passage?

A. Tasting with Eyes B. Flavors of Ice Cream

C. John Harrison’s Life D. One Cool Job

It seems that every week someone becomes “the first” or “the youngest” or even “the first married couple” to do something that doesn’t seem to be very useful to the rest of us.

Why do they do it? Don’t they have better things to do with their time and money? And why should I be interested anyway? Human beings have already climbed the highest mountains, sailed across the oceans and flown around the world. Many of these things were done a long, long time ago. There just isn’t anything left to explore nowadays. I suppose there’s still a lot of the universe left, and the bottom of the ocean is still a bit of a mystery, but you need a lot of technology to explore areas like that. So, those people who feel the need for adventure can only do things that have been done before.

In May of this year a British man became the first person to walk alone from Canada to the North Pole. Personally, if I wanted to visit the Arctic, I’d rather go as a tourist on a cruise ship, with a helicopter trip to the North Pole included in the price. But OK, this man decided that he wanted to walk. The problem was that he went in the spring when the ice begins to melt and break up. So he got stuck on a longely piece of ice and a plane had to be sent in to rescue him.

These sorts of rescues are making many Australians angry with these record breakers. People trying to break sailing or rowing records get into trouble in the seas. So the Australian navy has to send ships to save them and this costs the government millions of dollars. I suppose we can’t just leave them to drown but we should give the bill to the people who are rescued.

1.According to the author, the so-called record breakers .

A．do not benefit other people at all

B．inspire people to continue exploring

C．are boring and should be stopped

D．are usually not wealthy enough

2.We can infer from the second paragraph that .

A．there are no high mountains for people to climb

B．nothing is left for people to explore in the universe

C．it’s beyond ordinary people to explore the unknown

D．human beings could fly around the world long ago

3.Many Australians are angry because the record breakers .

A．often get into trouble

B．never use a cruise ship or a helicopter

C．never pay their own costs

D．satisfy their needs at the cost of others’ interest

4.What is the writer’s attitude towards the record breakers?

A．Positive. B．Negative.

C．Uninterested. D．Neutral（中立的）.

Have you ever noticed the colour of the water in a river or stream after a heavy rainfall? What do you think caused this change in colour? It is soil that has been washed into the river from the riverbank or from t}le nearby fields．

Components of Soft

Soil is made up of a number of layers（层），each having its own distinctive colour and texture．The upper layer is known as the litter．It acts like a blanket．limiting temperature changes and reducing water loss．The topsoil layer is made up of small particles of rock mixed with rotten plant and animal matter called humus（腐殖质），which is black and gives the topsoil its dark colour．This layer is usually rich in nutrients，oxygen，and water．Below the topsoil is the subsoil，a layer that contains more stones mixed with only small amounts of organic matter．This layer is lighter in colour because of the lack of humus．Beneath the soil lies a layer of bedrock．

Soil forms from the bottom up．Over time bedrock is attacked by rain, wind，frost, and snow．It is gradually broken down into smaller particles in a process called weathering．Plants begin to grow，and rotten materials enrich the topsoil．Most of the soil in Eastern Canada．for example．Was formed from weathered rock that was exposed when the ice disappeared l2．000 years ag0．

Water Beneath the Soil

Surface water collects and flows above the ground in lakes．ponds．and rivers．Once in the soil or rock，it is called groundwater．Gravity pulls groundwater through the soil in a process called percolation（渗透）．Eventually the water reaches a layer called the water table．Under this is bedrock through which water cannot percolate．

As water percolates downward，it dissolves organic matter and minerals from the soil and carries them to deeper layers．This causes a serious problem because plants require these nutrients for growth.

Soil pH

Soil can be acidic．neutral．or basic．The pH of the soil is determined by the nature of the rock

from which it was formed．and by the nature of t}le plants that grow and rot in it．

The acidity of rain and snow can lower the pH of the groundwater that enters the soil．By burning fossil fuels such as coal，oil and gasoline，humans have been contributing to higher levels of acidity in many soils．When fossil fuels are burned．gases are released into the air and then fall back to earth as acid rain．Acid soil increases出e problem of carrying nutrients to lower soil levels．As nutrients are removed，soil is less fertile．Plants grow more slowly in acidic soil，and also become easily attacked by diseases．

1.The layer of soil that provides necessary nutrients for plant growth is called．

A．1itter B．topsoil C．humus D．subsoil

2.According to the text．which of the following is NOT true?

A．Soil forms from weathered rock on the earth surface．

B．The deeper layer of soil is darker in colour than t}le surface soil．

C．Air pollution is partially responsible for acid soil．

D．Groundwater tends to carry away nutrients for plant growth．

3.We can infer from the passage that the water table lies ．

A．between the topsoil layer and the subsoil layer

B．in the subsoil layer above bedrock

C．between the subsoil layer and bedrock

D．in the bedrock layer beneath the subsoil

4.The underlined word “dissolve” is used to express the idea that organic matter and minerals from soil are ．

A．rushed away into the river

B．cleaned and purified by water

C．destroyed and carried away by water

D．mixed with water and become part of it

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