阅读理解
Linda and Betty were both twenty years old. They studied in a medical college. In June, after a
school year was over they decided to take a vacation in the country. They went to several towns and
villages, and visited some places of interest, saw and heard a lot of interesting things. They enjoyed
themselves very much.
One afternoon, they were going to stay overnight in a small town. It was too hot to go further and
they wished they could find a river and swim in the cool water. They were driving the car slowly while
they were looking around. Suddenly Linda saw a lake not far away. They drove there fast and stopped
the car by the lake. They looked around and found a man was sitting on a stone and fishing there. When
they took off their clothes and were going to jump into the water. the man came up to them and shouted, "Sorry, Madams' swimming is not allowed in the lake ! "
"Why didn't you tell us about it before we took off our clothes?" Betty said angrily.
"But it isn't forbidden to take off clothes by the lake, " said the man.
1. Linda and Betty were .
A. the same age
B. sisters
C. doctors
D. old
2. After a school year was over in June, they in the country.
A. had a good time
B. had a picnic
C. had a party
D. went to the cinema
3. _ , so they wanted to go for a swim in the cool water.
A. They were good at swimming
B. It was very hot
C. The rivers were beautiful
D. They were very tired
4. The man didn't want them "_ " in Chinese.
A. to fish in the lake
B. to take off their clothes
C. to swim in the lake
D. to get angry
5. The word "forbidden" means " " in Chinese.
A. 允许
B. 禁止
C. 同意
D. 干扰
，传送带以
＝10m/s 的速率逆时针转动.在传送带上端A无初速地放一个质量为ｍ＝0.5kg的黑色煤块，它与传送带之间的动摩擦因数为μ＝0.5.煤块在传送带上经过会留下黑色划痕 已知sin37o＝0.6，g=10
，（1）求煤块从A到B的时间。（2）煤块从A到B的过程中传送带上形成划痕的长度。
10
=
（1分） 
（1分）
后，煤块受到向上的摩擦力，由牛顿第二定律得：
（1分）
2
（1分）
（1分）
（1分）
（1分
（2分）
（2分）