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问题 选择题

若2是方程x2-2x+c=0的根，则c的值是（　　）

A．-3

B．-1

C．0

D．1

答案

根据题意，得

22-2×2+c=0，

解得c=0．

故选C．

选择题

经济学上有个古老的原理叫“劣币驱逐良币”，说的是在铸币时代，当那些“劣币”（低于法定重量或者成色的铸币）进入流通领域后，人们就倾向于将那些“良币”（足值货币）收藏起来。结果，市面上的“良币”越来越少，“劣币”越来越多。“劣币”之所以能驱逐“良币”，主要是因为[ ]

①作为流通手段的货币，不需要有价值

②在商品流通中货币充当商品交换媒介

③交易双方无法了解货币的成色或真伪

④劣币本身也是一种商品，也具有价值

A、①③

B、②③

C、②④

D、①④
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填空题
选用方框内的动词的适当形式填空:,
be,  have,  drive,  take,  do,  break,  sing,  go,  stop,  tell,  finish,  come
1. What _____ he usually _____ on Sundays?
2. Uncle Li _____ to Zhenzhen yesterday. He _____ back next week.
3. Grandpa _____ me an interesting story last night.
4. _____ your parents _____ working very late that day?
5. He came into the room and _____ a song for us all.
6. It _____ me half an hour to finish the work yesterday evening.
7. —_____ they _____ a get-together over there?
    —Yes, they are.
8. _____ the girl born in July or June?
9. He _____ goodbye to his father and left the home.
10. The man _____ the car very carelessly, so he had an accident.
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