According to popular folk tales, many animals are smarter than they appear. Dogs bark before earthquakes; cattle predict rainful by sitting on the ground. But cattle may have another hidden talent of being able to tell which direction is north.

    Small animals__ including birds__ are known to use the Earth’s magnetic (磁场的) fields in migration (迁徙), like a natural GPS ( Global Position System ). Dr. Begall and her colleagues wanted to know whether larger animals also have this magnetic sense. They investigated this possibility by studying images of 8,510 grazing (吃草) and resting cattle in 308 plains across the globe on Google Earth, a website that puts together satellite photographs to produce an image of the Earth’s surface.

    Grazing animals are known to orient (使朝向) themselves in a way that minimizes wind cold from the north and maximizes the warmth of the sun when they are cold. The study ruled out the possibility that the sun position or wind direction were major influences on the orientation of the cattle. The researchers therefore had to study a lot of cows grazing in lots of different places at different times of day, in order to average out these factors and see whether cattle could act like compass needles.

    The researchers concluded that cattle do generally orient themselves in a north-south direction. This north-south preference has also been noted in flies and honeybees. But unfortunately, even the high resolution of Google Earth is not powerful enough to tell which end of the cow is its head, and which its tail. The researchers were therefore unable to answer their research questions of whether cattle prefer to look north or south, and whether that differs in the northern and southern hemisphere.(半球)

1. Which of the following factors might affect Dr. Begall’s research result?

    A. Rainful.                B. Earthquakes.           C. Location.                       D. Cost.

2. What is the major finding of Dr. Begall’s study?

    A. Cattle orient themselves along a north-south axis.

    B. Magnetism cannot be studied scientifically.

    C. Animals prefer to look south.

    D. Google Earth is a reliable research tool.

3. Why were the researchers unable to get the answers to their research questions?

    A. Many cattle in their study were sitting on the ground.

    B. The cattle constantly change directions to avoid wind cold.

    C. There is a magnetic difference between the two hemispheres.

    D. They could not tell a cow’s head from its tail in the satellite pictures.

根据短文内容,从短文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。

As children grow, so does their desire to become independent. ---1--- As parents, our job is to find the right balance between kids’ desire for independence and the need to keep kids safe.

Kids need to be allowed, in fact encouraged; they like to be given certain risks. ---2- The right risk level for your child will depend on their age, developmental level, and character. It will change over time, and there are few hard and fast rules that apply to every child.

--3--- Every time you put your kids in the car you are putting them at risk. It is a fact of life.

So what is a parent to do? We must encourage them to explore their world while setting clear limits where safety is an issue. ---4--- We must let them run, but be prepared to catch them when they fall. We can’t take their steps for them; we can only point out the path.

It’s hard to imagine when they are small, but someday very soon they will be walking ,riding a bike, even driving ! ---5---Children do not often want to become independent.

A. It is impossible for any of us to live completely risk-free.

B. The goal for parents is to determine how much risk is appropriate.

C. Often they will become more willing to take risks and try new things.

D. Sometimes it is really tough for parents to encourage their children to be independent.

E. Someday they must face the world without us, and part of our job is to prepare them for that.

F. If we are overprotective, they are likely to grow up ill-prepared to meet and overcome the challenges they must inevitably(不可避免地)face. 

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