溢流堰的高低与频率振幅的关系是()。A、低溢流堰采用高频率操作方法 B、低溢流堰采

题型:多项选择题

问题:

溢流堰的高低与频率振幅的关系是()。

A、低溢流堰采用高频率操作方法

B、低溢流堰采用低频率的操作方法

C、高溢流堰采用高振幅的操作方法

D、高溢流堰采用低振幅的操作方法

E、高溢流堰采用低频率操作方法

F、高溢流堰采用高频率的操作方法

考点:选煤工程师重介质选煤重介质选煤题库
题型:多项选择题

Rita stepped into the cool, moving water. She pushed a black inner tube(内胎) in front of her. She had a worried look on her face because she had never floated down a river before.

“Let me hold your tube while you climb on,” said her father. He smiled at her. “There’s not a cloud in the sky. It’s a great day to be in the river, isn’t it?”

Rita looked out across the water. People were floating by on tubes. Some talked and laughed as they floated easily down the river. Others leaned(倚靠) back with hats pulled over their faces. None of them looked terrified.

“We’ll stay together,” said Rita’s father. “I’ll hold on to your rope(绳子).”

“Will we go very fast?” Rita asked.

“No,” said Dad. “We’ll move slowly for a while, and then it will get a little faster near the river’s bend(拐弯). Don’t worry, Rita. You’ll be fine.”

Rita looked at her tube. It gently(轻轻地) moved up and down in the water. She saw a girl of her own age float by. The girl seemed to be having fun. Suddenly Rita’s worries disappeared(消失).

“I’m ready to climb on and ride, Dad,” she said.

小题1:The underlined word “floated” in the reading means “________”.

A.划船

B.乘坐

C.漂浮

D.移动小题2:What is Rita’s problem in this story?   

A.She doesn’t like to be in cool water.

B.She is worried that she will get sunburned (晒伤的).

C.She is afraid to try something new.

D.She is afraid of boating.小题3:What’s the weather like in the story? 

A.Cloudy.

B.Rainy.

C.Windy.

D.Sunny.小题4:Which of these happened last in the story?  

A.Rita pushed her black tube.

B.Rita saw a girl of her own age.

C.Rita stepped into the water.

D.Rita looked worried.小题5:What’s the best title for this passage?

A.Rita’s Ride.

B.Rita’s Trip.

C.Rita’s Visit.

D.Rita’s Tube.

题型:多项选择题

仿照下面画线的句子,另写两句话,要求内容贴切,句式与示例相同。

挫折纵然无情。却给人无尽的砥砺:

失败固然残忍,却能使人趋于顽强。

一湾溪流。曲折回转中却能荡出山呜谷应的回响

_______________________________________________

题型:多项选择题

对于既需缴纳进口环节消费税又需缴纳增值税的进口货物,一般的计算过程为:先计算进口关税额,再计算增值税额,最后计算消费税额。

题型:多项选择题

下列说法中正确的是(    )

A.电子具有波动性,属于一种概率波

B.电磁波以机械振动的形式传播

C.光的偏振现象表明光是一种横波

D.超声波可以在真空中传播

题型:多项选择题

牵正散的君药是()

A.全蝎

B.白附子

C.白僵蚕

D.白附子、白僵蚕

E.全蝎、白附子

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