题干

生物检索表常用来鉴定生物的种类.请利用这张简单的“脊椎动物检索表”,鉴定出下列动物中属于S类动物的是(    )

1a 体外长有毛皮,胎生…哺乳类

1b 体外没有毛皮,卵生…2

2a 体外长有羽毛,体温恒定…R类

2b 体外无羽毛,体温不恒定…3

3a 表皮干燥,在陆地上产卵…S类

3b 皮肤湿润,在水中产卵…4.

A:

B:

C:

D:

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答案(点此获取答案解析)

C

同类题2

阅读下面短文,掌握其大意,从每题所给的A、B、C、D四个选项中,选出最佳选项。

    If life were a book and you were the author, how would you like the story to go? That is the question that 1 my life forever.

    One day I went home from the training of snowboarding with what I thought was the flu, and less than 24 hours later, I was in a 2 on life support with less than two percent 3 of living. It wasn't until days later that the doctors diagnosed me with a 4 blood infection.

    Over the 5 of 2.5 months, I lost the hearing in my left ear and both my legs below the knee. When my parents 6 me out of the hospital, I 7 that I had been put together like a patchwork(拼缝物) doll and I had to live with 8 legs. I was absolutely physically and emotionally broken, 9 streaming down.

    But I knew in order to move forward, I had to let go of the Old Amy and 10 the New Amy. It was at this moment that I asked myself that significant 11. And that is when it 12 me that I didn't have to be five-foot-five anymore,13 I could be as tall as I wanted. And 14 of all, I can make my feet the size of all the shoes. So there were 15 here.

    Four months later, I was back upon a 16. And this February, I won two Board World Cup gold medals, 17 me the highest ranked snowboarder in the world.

    So, instead of looking at our 18 and our limitations as something 19 or bad, we can begin looking at them as a wonderful 20 that can be used to help us go further than we ever know we could go.