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问题 选择题

下列各种现象不属于生命现象的是（　　）

A．蜜蜂采蜜

B．种瓜得瓜，种豆得豆

C．植物的根系向地生长

D．春雨绵绵

答案

“蜜蜂采蜜”反应了生物的生活需要营养物质，属于新陈代谢；“种瓜得瓜，种豆得豆”反应了生物具有遗传和变异的特性；“植物的根系向地生长”反应了生物能对外界刺激作出反应；“春雨绵绵”只是一种自然现象．

故选：D

解答题

已知f（x）=（x2+1）（x+a）

（1）当x∈（0，+∞）时，函数y=f（x）的图象上任意一点的切线斜率恒大于1，求a的取值范围．

（2）若y=f（x）在x∈（0，+∞）上有极值点，求a的取值范围．
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单项选择题

Mobile phones help us communicate everywhere, which is very important. They are good at emergencies, when you’ve (21) a car accident, for instance. A mobile phone (22) save your life! Mobile phones are also (23) because they have many good features--we can take photos and send them all over the world. But every coin has two sides. The (24) thing about mobile phones is that you have no privacy. My boss and friends find me whenever they want! I haven’t enjoyed a whole quiet day since the day I (25) my mobile phone. (26) disadvantage is that mobile phones make us lose good habits, such as punctuality. Before, when we (27) keep in touch so easily, if we had a date with someone, we tried our best to arrive (28) time. But now, because of the mobile phone, we are not afraid of (29) late any more, so, surprisingly enough, we make people wait! The third (30) I see is that I change my mobile phone once a year, and this means I’m spending (31) too much money on it. I think it is important to think (32) we use mobile phones. We should use things such as mobile phones, laptops, cameras, the Internet, and so on, (33) our needs. We can (34) our mobile phone when we don’t want to be disturbed by (35) . If we know how to use it, we can eliminate its disadvantages.

21（）

A.have 

B.made 

C.had 

D.crashed
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