Is this reason ________ to you for not lending you the money at that time?

1. A.
   the one he explained
2. B.
   he explained
3. C.
   why he explained
4. D.
   the one how he explained

We’ve heard about radiation from the damaged nuclear reactors in Japan reaching American shores. Experts say so far there is no reason to worry, and point out that we meet radiation every day. Where and how? NPR’s Renee Montagne posed that question to Peter Caracappa, a radiation safety officer and professor of nuclear engineering.
MONTAGNE: How many things emit radiation?
Dr CARACAPPA: Well, radiation and radioactive material is a part of nature. So everything that’s living has some amount of radiation coming from it—a very small amout. Plus there’s radiation in the ground and the air.
So the extremes are uranium in the soil to bananas?
Yes.
By the way, why do bananas have radiation?
Bananas have a lot of potassium(钾). And a small amount of potassium naturally is called potassium 40, which is radioactive
What’s the difference between radiation that’s harmful and not harmful?
Well, the term radiation can apply to a lot of different things. But the harmful radiation is ionizing(离子)radiation. It has enough energy that it can make chemical changes in material. We could get ionizing radiation from an X-ray, for example. It’s the kind of radiation that causes cancer.
The broader definition of radiation includes a lot of things that we call non-ionizing radiation. That includes everything like radio waves and visible light and your microwave.
So what then is the largest contributor of ionizing radiation?
For the natural sources of ionizing radiation, actually the biggest chunk of that tends to come from radon(氡), which is a radioactive material that is present in the air. It can become a concern when it builds up in low-lying areas of homes like basements.
Would it be fair to say that most people do not need to worry about the danger of being exposed to radiation?
I would say that the everyday exposure to radioation that we meet contributes an extremely tiny risk to our life or to our health compared to all of the other risks that we meet in our day-to-day life.
【小题1】We can infer from the first paragraph that radiation is______.

    Everyone should visit a lighthouse at least once .

The most important reason for such a visit is to realize how our ancestors (祖先) battled nature with the basic tools they had . They had only basic ways of creating light , and yet they found a way of using this simple technology in isolated (孤零零的) places to save ships from hitting rocks .

Secondly , visiting lighthouses will help us to understand the lives of lighthouse keepers .By their very nature , lighthouses were built on some rocks or cliffs . Thus , the lighthouse keepers often lived lonely lives . To walk around their small home , and imagine the angry storm outside beating against the walls , is to take a step towards understanding the lives they had.

The reasons for a visit to a lighthouse are not all so backward-looking in time . It is true that lighthouses were built in out-of-the way places . But on a pleasant sunny summer day. This very isolation has a untural beauty that many people will love to experience . Therefore , with the gentle waves touching all round the lighthouse . the visitor is likely to think it is a world preferable to the busy and noisy modern life.

Another reason for considering a visit is that the lighthouses themselves can be very attractive buildings . Mankind could often not be content just to put up a basic structure . but felt the need . even in such an isolated place , to build with an artistic touch . The result is a view for tired eyes to enjoy .

Finally , lighthouses have a romantic attraction , summed up by the image of the oil-skin coated keeper climbing his winding stairs to take care of the light to warn ships and save lives .

67．What is the reason to look back into the past of a lighthouse ?

       A．To escape from the busy and noisy city .

       B．To look for the tools used by our ancestors .

       C．To experience the natural beauty of a lighthouse .

       D．To learn about the living condition of lighthouse keepers .

68．The underlined phrase “out-of-the-way” in Paragraph of means         .

       A．far-away .           B．dangerous            C．ancient               D．secret

69．Lighthouses were often built with an artistic touch         .

       A．to attract visitors                                                                B．to guide passing ships

       C．to give a pleasant sight                         D．to remember lighthouse keepers

70．How many reasons are mentioned for a visit to a lighthouse ?

It is generally believed that we are getting cleaned when we step under a shower. We are, but we’re also giving a home to lots of tiny little creatures we didn’t even know about. A showerhead carries thousands of bacteria called Mycobacterium．These can cause problems like coughs and tiredness, and a general feeling of poorliness (身体不舒服). When you turn on the water, the bacteria go from the showerhead onto and into your body.

??? This is a finding of Norman R. Pace and his team at the University of Colorado, in the US. The scientists investigated bacteria in all kinds of human environment, including showers．Pace's team looked at 45 showerheads in nine American cities. They discovered that 30 percent of them had large amounts of flying Mycobacterium.

But Pace said that they pose few threats to the health．Only those with a weak immune system might need to worry．He told the New York Times that the bacteria are not as unpleasant as might be thought．He said that having a shower is no more dangerous than anything else we do in the morning．

But for those who feel sick about the idea of all those microorganisms (微生物), he had some advice. Let the water run for 30 seconds before getting into the shower. Why? The number of bacteria is smaller than that when the water is just turned on. If that seems like a waste of water, he added that you could also change your showerhead every few months.

??? However, Pace had good news too. He has also been testing the air in US subways. Apart from iron particles (粒子), which are ground off the track by the wheels of trains, subway air is fresh. The reason is that a train’s movement pumps fresh outdoor air into the tunnels.

??? Pace explained that he wanted to understand the natural microbial environments of public places. This kind of knowledge might help discover the microbes to be used in a bioterrorist (生物恐怖分子) attack.

1.From the finding of Norman R. Pace, after taking a shower, we might cough or feel tired because?????? .

A. it’s easy to get a cold when taking a bath

B. the showerhead carries many bacteria causing illness

C. we don’t get cleaned while showering

D. we don’t get a weak immune system

2.According to the passage, which of the following is TRUE?

A. Hot water could kill most of bacteria in showerheads.

B. Of 45 showerheads surveyed in nine cities, 30 carried large amounts of Mycobacterium.

C. Changing showerheads is the only way to avoid microorganisms.

D. Shower water contains much less bacteria after being left to run for 30 seconds.

3.We can learn from the third paragraph that ????? .

A. having a shower in the morning is more dangerous than at other time

B. the bacteria always threat people’s health

C. there is no reason to fear microorganisms for people with strong immune system

D. it is better to do some exercise in the morning than have a shower

4.The underlined word “pose” in the third paragraph probably means “______”．

A. cause     ?????????? B. avoid       ????????? C. describe ????????? D. promise

5.What contributes to fresh air in US subways?

A. The train’s movement.         ???????????????? B. Iron particles．

C. Train wheels. ???????????????????????????? D. Air conditioners on the trains．

For some time past,it has been widely accepted that babies—and other creatures—learn to do things because certain acts lead to “rewards(报酬)”,and there is no reason to doubt that this is true. But it used also to be widely believed that effective rewards, at least in the early time, had to be directly connected to such basic physiological(生理的) “drives” as thirst or hunger. In other words, a baby would learn if he got food or drink or some sort of physical comfort, not otherwise.?

It is now clear that this is not so. Babies will learn to behave in ways that produce results in the world with no reward except success in sight.?

Papousek began his studies by using milk in the normal way to “reward” the babies and to teach them to carry out some simple movements, such as turning the head to one side or the other.Then he noticed that a baby who had  had enough to drink would refuse the milk but would still go on making the learned response(回答) with clear signs of pleasure. So he began to study the children's responses in situations where no milk was provided. He quickly found that children as young as four months would learn to turn their heads to right or left if the movement “turned on” some lights—and indeed that they were able to learn some more turns to bring about(产生) this result,for example,two left or two right,or even to make as many as three turns to one side.?

Papousek's light experiment was placed directly in front of the babies and he made the interesting observation that sometimes they would not turn back to watch the light closely ?although? they would “smile and speak” when the light was on.Papousek concluded that it was not the sight of the lights which pleased them.It was the success they were achieving in solving the problem,in mastering the skill,and then there is a basic human nature to make sense of the world and bring it under control.?

According to the writer,babies learn to do things which _______.?

A. will satisfy their surprise B. will meet their physical needs?

C. are directly connected to pleasure D. will bring them a feeling of success

Papousek noticed in his studies that a baby _______.

A. would make learned responses when it saw the milk ?

B. would continue the simple movements without being given milk ?

C. would turn its head to right or left when it had enough to drink?

D. would carry out learned movements when it had enough to drink ?

In Papousek's experiment babies make learned movements of the head in order to _______.

A. be praised  B. please their parents?

C. be rewarded with milk D. have the lights turned on ?

The babies would “smile and speak” at the lights because _______.?

A. they succeeded in “turning on” the lights?

B. the sight of lights was interesting?

C. they need not turn back to watch the lights?

D. the lights were directly connected to some basic “drives”