如图,用球拍打击飞过来的网球时,若球击球拍的力为F1,球拍击球的力为F2,则(

题型:选择题

问题:

如图,用球拍打击飞过来的网球时,若球击球拍的力为F1,球拍击球的力为F2,则(  )

A.先产生F1后产生F2

B.F1和F2大小相等,方向相反

C.F1小于F2

D.F1大于F2

考点:牛顿第三定律
题型:选择题

某机电公司承接了某造纸厂的机电安装项目,包括自动化仪表(仪表的电缆槽采用螺栓连接)、变电所安装和电缆敷设等工程。电缆有电力电缆、信号电缆和控制电缆。按规定对仪表设备及材料进行开箱检验和外观检查,仪表安装完毕后按原则进行调校。

室外电缆敷设中,电缆在现场施放前必须()。

A.进行绝缘电阻测量

B.进行交流耐压及漏电电流测量

C.进行直流耐压及漏电电流测量

D.进行充油电缆的绝缘油的试验

E.进行漏电电压的测量

题型:选择题

词汇运用

1. Her cheerful spirits ________(感染了) the whole class.

2. As a young boy he showed great interest in ________(科学) and did many ________(科学的)

experiments in his spare time,which would make him a great ________(科学家) in time.

3. After a long discussion,they ________(得出结论) that the man was lying.

4. Today I have some important things ________(处理).

5. The baby was left ________(毫无遮蔽的) to the wind and rain.

6. We are ready to ________(承担责任) for what happened.

7. The teacher ________(宣布) that we would have a few days off and there would be ________(通知) for the exact time.

8. I ________(接到指令) to wait here until the lecturer arrives.

9. Does smoking ________(对……起作用;贡献) lung cancer?

10. Our idea to set up a music club in the neighbourhood meet many ________(拒绝).

题型:选择题

从什么时候开始,岗位责任制被逐步引入图书馆,并得到广泛应用()

A、20世纪60年代

B、20世纪70年代

C、20世纪80年代

D、20世纪90年代

题型:选择题

左归丸的功用是()

A.温补肾阳,填精补血

B.滋阴补肾,填精益髓

C.补益肝肾,强壮筋骨

D.滋阴补肾,涩精止遗

E.填精补髓,滋阴降火

题型:选择题

病人应首先查

A.血常规

B.腹部X线

C.腹部B超或CT

D.FTC

E.ERCP

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