如图是自行车示意图,根据你对自行车的认识,你认为自行车在设计上,为了减小摩擦的是

题型:选择题

问题:

如图是自行车示意图,根据你对自行车的认识,你认为自行车在设计上,为了减小摩擦的是:

[ ]

A.自行车轮上的花纹

B.自行车脚踏板上的花纹 

C.用橡胶制作自行车的刹车皮

D.自行车轮转轴内的小滚球

考点:影响摩擦力大小的因素
题型:选择题

阅读理解。

     Dick was born in a poor family. His father had a small boat and went fishing in the morning and sold

the fish in the market in the afternoon. Then he bought some food for his family. When winter came, they

were often hungry. One morning the hungry man fell into the river and wasn't found. Dick's mother left

her three-year-old son without saying good-bye. His aunt had to look after him.

     Twenty years passed. Dick became a tall, strong man. He found work on a farm. He worked hard

and wanted to get more money. He often went to see his aunt with some nice presents. The woman was

very happy but one day she died in a traffic accident. The young man was very sad. After he buried her,

he decided to buy a beautiful tombstone(墓碑)for her. He went to town and came in a shop, but all the

tombstones were too expensive. He asked, "Do you sell an old tombstone, sir?" "Yes, we do, sir, "

answered the shopkeeper. "Is it as expensive as the new one?"

     "No, it's much cheaper," said the man. "But another name was engraved (刻) on it." "It doesn't matter,

" said Dick. "My aunt couldn't read. "

1. If     ___ , the family members were hungry.

A. Dick's father could catch no fish in winter  

B. Dick's father had a boat in winter

C. Dick's father had to look after him in winter  

D. no food was sold in winter

2. The woman had to look after Dick because  __     .

A. she was rich            

B. his father asked her

C. she was kind-hearted    

D. the boy loved her

3. Dick wanted to get more money to     __ .

A. marry a wife            

B. give his aunt nice presents

C. buy a farm              

D. build a house

4. Dick often went to see his aunt because       _ .

A. she felt lonely          

B. she was often ill

C. she had no children      

D. with her help he grew up

5.Dick wanted to buy an old tombstone because  __  _ .

A. he had enough money to buy a new one

B. his aunt couldn't read whose name was engraved

C. his aunt wasn't going to mind it    

D. nobody knew what his aunt's name was

题型:选择题

案例摘要:处方:左旋多巴100g,酒石酸50g碳酸氢钠56g,羧甲基纤维素20g,微晶纤维素30g,滑石粉6g,硬脂酸镁2g,共制成1000片。

微晶纤维素在片剂中的作用是()

A.崩解剂

B.润滑剂

C.黏合剂

D.助流剂

E.稀释剂

题型:选择题

十枣汤的功用是()

A.养血润燥

B.养血安神

C.补气健脾

D.益气补血

E.攻逐水饮

题型:选择题

“新大陆”是指()

A.美洲

B.非洲

C.南极洲

D.大洋洲

题型:选择题

打磨焊道作业时,为何必须戴绝缘手套,手套应保持干燥?

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