电功和电功率的单位分别是( ) A.千瓦时和焦耳 B.千瓦和瓦特 C.焦耳和瓦特

题型:选择题

问题:

电功和电功率的单位分别是(  )

A.千瓦时和焦耳

B.千瓦和瓦特

C.焦耳和瓦特

D.千瓦和千瓦时

考点:电功的概念电功率,额定功率
题型:选择题
综合填空(共8小题,计分8分)从下面方框中选择适当的词填入短文中,使短文通顺正确(注意有些词要用适当的形式)。

hobby   boy   angry   spend   lose   beautiful    difficult   take

 
 


One day, Mr. White told the class to get ready for a hobby show. The students 小题1: the whole morning getting what they were going to show.
All the students came back on time but Bob, the laziest 小题2: in his classmates’ eyes. It seemed that it was very 小题3: for Bob to have a hobby. But to their surprise, Bob came back with many 小题4:stamps in his hand. Mr. White was very happy after watching them. However, Bob was going to 小题5: them back.
“Bob, you can’t take them back until the others watch them this afternoon,” said Mr. White.
“But I am sorry they are my brother’ s,” he answered. “He doesn’t want them to be out of our home for long. He’s afraid that they will be 小题6: .”
“Bob, you should show some of your own 小题7: here, not someone else’s. Mr. White became kind of angry.
But Bob’s words made him even 小题8: . “Mr. White, it’s true that I have a hobby. My hobby is watching my brother collecting stamps.”
题型:选择题
计算:
(1)-23÷
4
9
×(-
2
3
2
(2)[1-(1-0.5×
1
3
)]×[2-(-3)2].
(3)-|-3+2
1
3
|-|-
1
3
|2+(-
1
3
2×(-1)9×(-2)3
(4)-22×(-3.14)-3.14×(-
1
2
)×(-6);
(5)(
7
4
-
7
8
-
7
12
)÷(-
7
8
)+(-
8
3
).
题型:选择题

Tamm-Horsefull蛋白属于()

A.球蛋白

B.糖蛋白

C.白蛋白

D.黏蛋白

E.免疫球蛋白重链

题型:选择题

民用航空气象地面观测按观测内容分为()、特殊观测和事故观测。

A.常规观测

B.日常观测

C.例行观测

D.普通观测

题型:选择题

新加入者要进入某个新的行业总会遇到种种困难,从而形成进入障碍,这种障碍所包括的主要因素有()。

A.规模经济

B.资源条件

C.产品差异优势

D.资金需求

E.原有企业对新进入者的态度

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