题目内容
[ ]
B. for; against
C. with; for
D. with; at
根据对话内容，从对话后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
—Hello,Professor Smith.The summer vacation is coming. 【小题1】
—I am going to Miami Beach,Florida for two weeks.
—How will you get there?
— 【小题2】
—Does it cost a lot?
—No.The cost is lower out of season.It is my first time to travel by air. 【小题3】.
—Don’t worry.Are your family going with you ?
—Yes.We plan to go swimming in the ocean ,enjoy the sunshine on the beach and go water-skiing
— 【小题4】 .
—Yeah,they are crossing off the days on the calendar.Are you going go Europe again this summer?
—No,not this time. 【小题5】 .
—Egypt? It is really a place full of mystery.Have a good trip.
—Thank you .The same to you.
| A．In fact,I am a little nervous. |
| B．When are you leaving? |
| C．What’s your plan for the vacation? |
| D．I plan to go there by train. |
F、I am going to visit some old friends in Egypt.
G、Your children must be excited about it.
ABCD请按实际情况填写。其他请参照下表填写。
A, B, C, D, E(AB), F(AC)
| A. Control of Respiration B. Basic tips for preserving cut flowers C. Role of Respiration D. Most Important Aspect of Flower Care E. Need for Clean Water F. Ways of Stopping Respiration |
While everybody enjoys fresh cut flowers around his house, few people know how to keep them for as long as possible. This may be done by keeping in mind a few simple facts. The key to keeping fresh cut flowers for a week or more without floral preservatives(which contain biocides that kill bacteria and fungus) is to keep the water fresh and the stems free of air pockets so they can continue to draw up water.
【小题2】
An important thing to remember about cut flowers is that they are sensitive to temperature. For example, studies have shown that cut carnations(康乃馨) retain their freshness eight times longer when kept at 12℃ than when kept at 26℃. Keeping freshly harvested flowers at the right temperatures is probably the most important aspect of flower care.
【小题3】
Flowers are not intended by nature to live very long. Their biological purpose is simply to attract birds or insects, such as bees, for pollination (授粉). After that, they quickly dry up and die. The process by which flowers consume oxygen and produce carbon dioxide, called respiration (呼吸), generates the energy the flower needs to give the flower its shape and colour. The making of seeds also depends on this energy. While all living things respire, flowers have a high level of respiration. A result of all this respiration is heat, and for flowers the level of heat relative to the mass of the flower is very high. Respiration also brings about the eventual death of the flower. Thus the greater the level of respiration, the sooner the flower dies.
【小题4】
How, then, to control the rate at which flowers die? By controlling respiration. How is respiration controlled? By controlling temperature. We know that respiration produces heat, but the reverse is also true. Thus by maintaining low temperatures, respiration is reduced and the cut flower will age more slowly.
【小题5】
Another vital factor in keeping cut flowers is the quality of the water in which they are placed. Flowers find it difficult to “drink” water that is dirty or otherwise polluted. Even when water looks and smells clean, it almost certainly contains harmful substances that can endanger the flowers. To rid the water of these unwanted substances, household chlorine bleach (含氯漂白剂) can be used in small quantities. It is recommended that 15 drops of chlorine bleach(at 4% solution) be added to each litre of water. The water and solution should also be replaced each day.
Before going outside in the morning, many of us check a window thermometer(温度计)for the temperature. This helps us decide what to wear. _____76____. We want our food to be a certain coldness in the refrigerator. We want it a certain hotness in the oven. If we don’t feel well, we use a thermometer to see if we have a fever. We keep our rooms a certain warmth in the winter and a certain coolness in the summer.
Not all the thermometers use the same system to measure temperature. We use a system called the Fahrenheit scale. But most other countries use the Centigrade scale.
Both systems use the freezing and boiling points of water as their guide._____77_____ .
The most common kind of thermometer is made with mercury(水银)inside a clear glass tube. As mercury (or any other liquid ) becomes hot, it expands. As it gets colder, it contracts(收缩). That is why on hot days the mercury line is high in the glass tube._____78______.
First. Take a clear glass juice bottle that has a cap ; fill the bottle with coloured water. Tap a hole in the center of the cap using a hammer and thick nail. Put the cap on the jar. Then stick a plastic straw(吸管) through the nail hole.
______79______.
Finally. Place a white card on the outside of the bottle and behind the straw. Now you can see the water lever easily.
______80____.
As the temperature goes down, the water will contract, and the lever in the straw will come down. Perhaps you will want to keep a record of the water lever in the straw each morning for a week.
|
A．We use and depend on thermometers to measure the temperature of many other things in our daily lives. |
|
B．Thermometers measure temperature, by using materials that change in the same way when they are heated or cooled. |
|
C．Now that you know this rule you can make a thermometer of your own that will work. |
|
D．The water will rise in the straw. As the temperature of the air goes up, the water will |
expand and rise even higher.
E．They label these in different ways. On the Fahrenheit scale water freezes at 32 degrees and boils at 212 degrees. On the Celsius scale water freezes at 0 degrees and boils at 100degrees.
F．Take wax (you may use an old candle if you have one) and melt some of it right where the straw is struck into the cap to seal把..粘住) them together.
G．People use thermometers which are made by themselves when travelling around the
world.