倾角为θ=30°的斜面体放在水平地面上,一个重为G的球在水平力F的作用下,静止在

题型:选择题

问题:

倾角为θ=30°的斜面体放在水平地面上,一个重为G的球在水平力F的作用下,静止在光滑斜面上,若将力F从水平方向逆时针转过某一角度a后,仍保持F的大小,小球和斜面也仍能保持静止,则此时水平地面对斜面体的摩擦力F1;那么F和F1的大小分别是

A.

B.

C.

D.

考点:力的合成力的分解
题型:选择题

阅读理解。

     Cindy likes eating ice cream very much. She often buys ice cream in the shop and takes them home.

So does her husband (丈夫). One day her husband sees the ice cream and thinks, "Good! Now, I can have

a delicious dessert."

     When Cindy comes home from work in the evening, the ice cream is not there and her husband says,

"Oh, you see the bridge (冰箱) is broken. It's not cold at all." "Really?" Cindy says. And at the same time,

she puts her husband's arm into the fridge. "Keep it for an hour. Don't move it away before I come back."

She goes to cook dinner. "Oh, no." her husband shouts loudly.

1. What does Cindy like to eat?

A. ice cream

B. eggs

C. fish

D. meat

2. What does "So does her husband" mean?

A. 她丈夫不爱吃

B. 她丈夫也是

C. 她丈夫是的

D. 所以是她丈夫

3. The bridge is broken. Is it true?

A. Yes, it is

B.  No, it isn't

C. Yes, it isn't

D. No, it is.

4. Does Cindy know her husband eats her ice cream?

A. Yes, she does.

B. No, She doesn't.

C. I don't know.

D. It doesn't tell.

5. Cindy buys ice cream from _____.

A. shop

B. restaurant

C. dessert shop

D. hotel

题型:选择题

下列产品属于撒哈拉以南的非洲进口商品的是 [ ]

A.铜矿石

B.活牲口

C.木材

D.汽车

题型:选择题

患者男性,38岁,尿毒症,血压185/110mmHg,心率60次/分,ECG显示ST-T波改变,维持血液透析4年,拟行同种异体肾移植手术。

开放吻合的血管后移植肾灌注不良不宜采用()。

A.吸氧

B.快速输血输液

C.肾上腺素O.5mg/min

D.25%葡萄糖100ml静脉推注

E.多巴胺2~3μg/(kg·min)

题型:选择题

中国C919是第几款国产大型客机()

A.第一款

B.第二款

C.第三款

D.第四款

题型:选择题

在市场经济中,作为经济活动参与者的个人和企业的关系是()

A.个人和企业相互矛盾

B.个人和企业相互依存

C.个人和企业相互欺骗

D.个人和企业没有关系

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