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如图所示是骨伤科病房中一种常用的牵引装置．若所挂重物的质量为M，则在图示情况中，病人脚部所受的拉力是______．（不计滑轮摩擦及滑轮重力）

答案

对与滑轮接触的一小段绳子受力分析，如图受到绳子的两个等大的拉力

F1=F2=Mg

根据平衡条件得

2F1cosθ=F

解得

F=2Mgcosθ=

2
Mg

故答案为：

2
Mg

阅读理解
阅读理解。
下面是Sandy手机上的短信，请根据内容选择正确答案。
No. 1Sandy:
     I am going to have a Christmas
Party next weekend. Are you
coming? 
                                      From 
                                     Grace
No. 2

Sandy:
      I found a new brand (品牌)
of dog food. My Tim just likes
it. Would you get some for your
 Luckey?
                                    Yours
                                     Wu

No. 3Sandy: 
     The Fugitive is on now at
Present Theater. Want to see it? 
                                     Yours 
                                      Chris 		No. 4 Sandy: 
      Ring me up, please
                                      Steve

No.5Mrs. Sandy: 
      Mr. Brown said your car is
OK.And now you can go and get
it from 9:00 a.m. to 5:00 p.m. 		No. 6Sandy:
      Buy some bread on your way home.
Thanks.
                                        Sue
1. When is Grace going to have a party?
[ ]
A: This weekend
B: This Friday
C: Next weekend
D: Next month
2. What is The Fugitive?
[ ]
A: A book
B: A movie
C: A song
D: A ball game
3. What did Mr. Brown do for Sandy?
[ ]
A: He examined her car.
B: he wanted to buy her car.
C: He prepared dinner for her.
D: He found a new brand of dog food.
4. What are Tim and Luckey?
[ ]
A: A man and a dog.
B: a man and a woman.
C: Two kinds of food.
D: Wu's and Sandy's dogs.
5. Who of the following persons is probably a member in Sandy's family?
[ ]
A: Grace.
B: Wu.
C: Sue.
D: Steve
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单项选择题 A1/A2型题

关于药品说明书说法错误的是（）

A.由国家食品药品监督管理局予以核准

B.药品说明书的文字表述应当科学、规范、准确

C.药品说明书应当使用容易理解的文字表述，以便患者自行判断、选择和使用

D.药品说明书应当包含药品安全性、有效性的重要科学数据、结论和信息

E.药品说明书用以指导安全、合理使用药品
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