阅读理解。 Domestic (驯养的) horses now pull pl

问题：

阅读理解。

     Domestic (驯养的) horses now pull ploughs, race in the Kentucky Derby, and carry police. But early

horses weren't tame (驯服的) enough to perform these kinds of tasks. Scientists think the first interactions

humans had with horses were far different from those today.

     Thousands of years ago, people killed the wild horses that lived around them for food. Over time, people

began to catch the animals and raise them. This was the first step in domestication.

     As people began to tame and ride horses, they chose to keep those animals that had more desirable

characteristics. For example, people may have chosen to keep horses that had a gentle personality so they

could be ridden more easily. People who used horses to pull heavy loads would have chosen to keep stronger

animals. Characteristics like strength are partly controlled by the animals' genes. So as the domesticated horses

reproduced, they passed the characteristics on to their young. Each new generation of houses would show

more of these chosen characteristics.

     Modern day horse breeds come in a wide variety of shapes and sizes. This variety didn't exist in the horse

population before domestication. The Shetland horse is one of the smallest breeds-typically reaching only one

meter tall. With short, strong legs, the animals were bred to pull coal out of mine shafts (矿井) with low

ceilings. Huge horses like the Clydesdale came on the scene around 1700. People bred these heavy, tall horses

to pull large vehicles used for carrying heavy loads.

     The domestication of horses has had great effects on societies. For example, horse were important tools

in the advancement of modern agriculture. Using them to pull ploughs and carry heavy loads allowed people

to farm more efficiently. Before they were able to ride horses, humans had to cross land on foot. Riding horses

allowed people to travel far greater distance in much less time. That encouraged populations living in different

areas to interact with one another. The new form of rapid transportation helped cultures spread around the

world.

1. Before domestication horses were _____.

A. caught for sports

B. hunted for food

C. made to pull ploughs

D. used to carry people

2. The author uses the Shetland horse as an example to show _____.

A. it is smaller than the Clydesdale horse

B. horse used to have gentle personalities

C. some horses have better shaped than others

D. horses were of less variety before domestication

3. Horses contributed to the spread of culture by _____.

A. carrying heavy loads

B. changing farming methods

C. serving as a means of transport

D. advancing agriculture in different areas

4. The passage is mainly about _____.

A. why humans domesticated horses

B. how humans and horses needed each other

C. why horses came in different shapes and sizes

D. how human societies and horses influenced each other