七选五专练

七选五专练（二）

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。

A

A young lady was standing on the corner with a map in her hand. She looked puzzled.1I wondered why. Maybe it was because of the way she was dressed. She wore a dirty dress and looked pale.

As I crossed the street and came closer to her I asked if she wanted help.2As it turned out she was looking for the hospital. I felt wonderful just reaching out, and taking that extra moment to help.

Many times in these situations I end up walking a person to where he or she is going when giving directions would be too complicated.3Many years ago, we travelled in Japan and needed directions. A kind Japanese who saw our problem came to us and helped us out. This man just took my heavy bags and guided us to where we needed to be. We could not speak any Japanese while the man could not speak any English.4

Sometimes when I do a special favor for a stranger, the person will say, “I hope I can do something for you one day to return the favor.” 5 But I hope that when they come across a situation where someone needs their help, they will be willing to reach out as well.

A. Although we could not communicate through words, we communicated through the heart.

B. They already have done something for me by giving me the opportunity to help them.

C. I like helping people this way due to my own experience.

D. Several people passed by, looked at her but did not stop.

E. It is never too late to do others a favor.

F. These words made me feel quite warm.

G. She thanked me and smiled in relief.

B

Livestock (牲畜) cloning is the practice of cloning sheep, cattle and other livestock species as a way to improve efficiency. The basic idea behind livestock cloning is to clone animals that have certain qualities, such as cows that produce more milk or meat.1

However, this practice is very controversial, and livestock farmers have been hesitant to adopt it fully because of public opposition and certain inefficiencies.

In technical terms, livestock are cloned by taking cells from one animal and using them to fertilize eggs (使卵子受精). Scientists take the fertilized eggs and put them in female animals.2Many animals are born with abnormal shapes. Scientists are looking for ways to improve the process and make it less expensive to adopt on a wider scale.

3For example, if farmers were able to take only their very best animals and recreate them many times, they could potentially be more productive.

There are also some potential problems with cloned livestock.4For example, when a disease hits, there are usually individuals who cannot be harmed by the disease or are more resistant, and they will generally survive. If all the animals were genetically (在基因方面) identical or similar, this sort of disease could totally destroy an entire generation of livestock, leaving the world with a massive food shortage.

In addition to concerns about genetic diversity, there are other concerns about cloning.5There are also some people who worry that livestock cloning research may be a gateway to introducing human cloning, which is widely disapproved of.

A. Are the surviving clones really clones

B. Therefore, the new species is expected to be better.

C. The biggest one arises from a reduction in genetic diversity.

D. Cloned livestock have the potential to provide some major benefits.

E. Cloning animals shows us what might happen if we try to clone humans.