Question

【题目】根据短文内容，从下面方框中选择适当的选项补全短文

Do you have a tail？ Of course not， we know． But tails are like opinions． actually， everyone

has them： fishes， birds， most reptiles， and even some of our closest relatives

Since tails tirst evolved（进化） at least 500 million years ago． Geckos （壁虎）use them to store fat． birds use them to steer through the air， But for most mammals （哺乳动物）．【1】Yet， as you get closer to humans on the evolutionary tree， tails disappear， Gorillas（大猩猩）don' t have them， and neither do chimps（黑猩猩） or any other apes （类人猿） including us， of course， To understand why， take a look at how we walk．

【2】walking like this gives us a huge advantage because unlike four﹣legged animals．which have to pour energy into every step they take， two legs take advantage of gravity（重力），which does some of the work for us． You see， each time we take a step， gravity pulls us forward．The end result is that when we walk， we use around 25% less energy than walking on all fours， and this way of getting around also totally climinates（淘汰） the need for a tail．

It's said that you can still see a reminder of a time when our ancient ancestors had one． Just look at a human spine（脊椎）．【3】That's your tailbone． It's all that's the rest of our tail．

Now， babies are born with what looks like a tail， but that's not what's really going on． Most often， these tails are actually a parasitic twin（寄生虫）． These types of tails usually form as a birth fect（瑕疵）．【4】

So the tail of humans has gone， it's the result of evolution millions of years Will humans be much taller， stronger or smarter in the future？

A． Nowadays， humans can walk completely upright．

B． And in these situations， doctors will advise to remove the tails with no harm to the babies

C． they serve one major purpose﹣﹣balance．

D． You can see how the last few bones are partly fused（融合） together

Answer 1

【答案】

【1】C

【2】A

【3】D

【4】B

【解析】

短文大意：本文是科普类阅读，介绍了人类“尾巴”的进化过程，指出人类的尾巴是数百万年进化的结果，预计人类将来会变得更高、更强、更聪明。

【1】C but但是，表转折；根据前句Geckos use them to store fat, birds use them to steer through the air可知列举了尾巴的作用，备选项But for most mammals, they serve one major purpose—balance介绍的是哺乳动物尾巴的重要作用﹣﹣保持平衡．故选C。

【2】A 根据后句walking like this gives us a huge advantage because unlike four﹣legged animals像这样走路给了我们巨大的优势，因为不像四条腿的动物；结合选项可知说现在人类可以完全直立行走．Nowadays, humans can walk completely upright符合文意，故选A。

【3】D 根据前句Just look at a human spine看看人类的脊椎；结合选项，可知You can see how the last few bones are partly fused together介绍了看到的东西：最后几根骨头是如何部分融合在一起的，符合句意，故选D。

【4】B 根据前句These types of tails usually form as a birth fect这些类型的尾巴通常形成一个瑕疵，可知在这种情况下，医生会建议在不伤害婴儿的情况下切除尾巴，And in these situations， doctors will advise to remove the tails with no harm to the babies符合文意，故选B。