已知关于x的方程ax2+2x+1=0至少有一个负实根，则实数a的取值范围（ ）A
题型：选择题
问题：
已知关于x的方程ax2+2x+1=0至少有一个负实根，则实数a的取值范围（ ）
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题型：选择题
We often hear that children wish they were grown-ups, and that old people wish they were young. __小题1:__ The happiest people enjoy what each age gives them without wasting their time in useless regrets.
__小题2:__ A child is fed, looked after and loved by all grown-ups like parents or grandparents. __小题3:__ However, for older people they often lose their interest in those things.
On the other hand, a child may also have some pains with him. __小题4:__ He is often told not to do something. He will certainly be shouted at for doing something wrong.
When a child grows up, he can no longer expect others to pay for his food, clothes and many other things. __小题5:__ If he still spends most of his time playing as he used to in 
childhood, he will go hungry. If, however, he works hard and has no trouble, he can build up his own position in society with great happiness.
A．What’s more, life is always giving new things to him.
B．He enjoys his life very much.
C．And if he wants to live comfortably, he has to work.
D．He is not so free to do what he wishes to do.E. Life is always sad for old people.
F. Each age has its own pleasures and its own pains.
Childhood is a time when there are few duties.