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问题 单项选择题

在用衰减曲线法整定调节器参数时，其操作过程应是（）。

A.切除积分、微分作用，改变PB；使出现等幅振荡，记录此时PB和振带周期Ts

B.切除积分、微分作用，改变PB；使动态过程符合4∶1衰减比，记录PB和Ts

C.切除比例、微分作用，改变Ti使出现等幅振荡，记录Ti和Ts

D.切除比例、微分作用，改变Ti使动态过程符合4∶1衰减比，记录Ti和Ts

答案

参考答案：B

阅读理解

根据句子的上下文语境，给下划线的单词或词组选择恰当的英文解释。

小题1:To commemorate the baby’s birth they put her name on the bell.

小题2:What happens at births, weddings, and funerals in your country?

小题3:Over five hundred mourners came to his funeral.

小题4:The President of the Republic placed a wreath on the tomb.

小题5:Stop all the clocks, cut off the telephone, prevent the dog from barking with a juicy bone, silence the pianos and with muffled drum, bring out the coffin, let the mourners come.

A．cannot be heard clearly

B．to do something to show that you remember and respect someone important or an important event in the past

C．something gradually decreases

D．to make a long low sound expressing pain or unhappiness.E. a circle made from leaves or flowers that you put on a grave

F. a religious ceremony for burying or burning a dead person

G. someone who attends a funeral, especially a relative of the dead person
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单项选择题

The scope of freight forwarder's service on behalf of consignors includes( )．

A．paying the freight to the insurer

B．arranging import customs clearance

C．booking space with consignee

D．booking space with carder
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