在特定负载下,改变机械特性而得到的转速称为() A.速度变化 B.速度调节 C.加速

题型:单项选择题

问题:

在特定负载下,改变机械特性而得到的转速称为()

A.速度变化

B.速度调节

C.加速度

D.减速度

考点:注册电气工程师电气传动电气传动题库
题型:单项选择题

阅读理解。

     Cold air. Snow. Shorter days. We are in winter now.

     Winter is the coldest season of the year. It comes between autumn and spring. For us, the winter

months are usually November, December and January. But that is only because we live in the northern

part of the Earth.

     In China, winter is the time between the beginning of winter, and the beginning of spring. But, this

is the time that the southern part of the Earth, has its summer. Imagine when we are playing with snow,

Australian kids are enjoying ice cream!

     Winter isn't always gray. It can also be bright. Here's how.

     Put on a holiday play and try acting. Ask your cousins or classmates to come to your house and make

beautiful clothes and write a play. Act it out for your family.

     Play around. Go outside and enjoy yourself. Make a snowman with your friends.

     If you really have to stay indoors, give your room a clean and decorate (装饰) it. You'll find it a lot

of fun.

1. What does this passage mainly talk bout? [ ]

A. The winter season and fun winter activities.

B. Ways to decorate houses.

C. The difference between China and Australia.

D. The colours linked to winter.

2. Why are Australian kids eating ice cream when it's winter in China? [ ]

A. Because they are crazy about ice cream.

B. Because winter in Australia is not as cold as that in China.

C. Because it's summer in Australia when it's winter in China.

D. Because they don't have much to do in winter.

3. Which of the following statements is NOT true according to the passage? [ ]

A. The northern and southern parts of the Earth have different winter months.

B. Winter can be fun if you find interesting things to do.

C. The writer thinks it's great fun to clean your house and decorate it.

D. Australian kids enjoy having ice cream on winter days.

从短文中选出一种你喜欢的活动,并说明原因。 

     I think it will be great fun to 4. ____ this winter because I like to 5. ____. Also, it is 6.____ and it can

7.____. I'll try it out soon. 

Find words from the passage to fill in the blanks:

     In China, the winter months are usually November, December and 8.____. But it's different in Australia.

The winter in China is 9.____ in Australia because it is in the 10.____ part of the Earth.

     Winter is not always 11.___. You can have lots of fun. Try 12.____ a play and acting it out with your

cousins or friends. Or you can play 13.____ outside and make a 14.____. If you have to stay 15.____, clean

up your house and 16.____ it with fun pieces.

     Just enjoy winter!

题型:单项选择题

病历摘要:一初产妇,29岁,妊娠32+周, * * 流血两次,量不多,今日突然 * * 流血多于月经量,无腹痛,查血压100/80mmHg,脉搏96次/分,宫高30cm,腹围85cm,臀先露,未入盆,胎心音144次/分。

下列哪些是前置胎盘的表现?()

A.先露下降受阻

B.无痛性 * * 流血

C.子宫下段可闻及胎盘血流音

D.子宫张力高,胎心音不易闻及

E.宫底高度与孕月相符

题型:单项选择题

中华文明源远流长,绵延不止,成就辉煌。有文字可靠的历史从什么时候开始。

A.夏朝

B.商朝

C.西周

D.战国

题型:单项选择题

心肌梗死的图形演变分期;错误的是()

A.超急性期

B.近期

C.急性期

D.陈旧期

E.晚期

题型:单项选择题

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