下列哪个剂量以下辐照的食品对人体是安全的（） A.lkGy B.10kGy C.10

A地海拔高度是﹣20m，B地海拔高度是﹣50m，A、B两地海拔高度相差（    ）m。

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     In Canada you can find dogs, cats, horses, etc. in almost every family. These are their pets. People love these pets and have them as their good friends. Before they keep them in their houses, they take them to

animal hospitals to give them injections(注射) so that they won't carry diseases. There are many special

animal food stores, though people can get animal food in almost every kind of store. Some people spend

around two hundred Canadian dollars a month on animal food. When you visit people's houses, they will

be very glad to show you their pets and they are very proud of them. You will also find that almost every

family has a bird feeder in their garden. All kinds of birds are welcome to come and have a good meal. They are free to come and go and nobody is allowed to kill any animal in Canada. They have a law against

killing wild animals. If you killed an animal, you would be punished. If an animal happened to be hurt by a

car, people would be very sad about it. 

     People in Canada have many reasons to like animals. One of them might be: Their family ties are not as close as ours. When children grow up, they leave their parents and start their own lives. Then the old will

feel lonely. But pets can solve this problem. They can be good friends and never leave them alone.

1. The passage mainly talks about ______.

A. how to keep disease from pets

B. pets in Canada

C. how to take good care of pets      

D. life of the old in Canada

2. They give their pets injections before keeping them in their houses because ______.

A. the pets are sick      

B. the pets are wild

C. they want to stop them from carrying disease

D. they want them to sleep on the way home

3. This passage shows that Canadians ______.

A. hate animals                

B. often kill animals

C. love animals

D. don't keep pets inside houses

4. Which of the following is TRUE?

A. People buy animal food only at the animal food stores.

B. Pets eat better than people.

C. Almost every family has a birdcage in his house.

D. Any bird can come to the bird feeders to eat.

人造花若沾上灰尘可用刷子清理，不怕水的人造花可（）。

A、在油中清洗

B、在水中加入洗洁精清洗

C、在有机溶剂中清洗

D、在冰冻下清洗

龙胆泻肝汤治疗胁痛的作用是：

A．祛瘀通络
B．疏肝理气
C．抑肝扶脾
D．清热利湿
E．以上都不是

轧制压力是轧件变形时金属作用于轧辊上的压力。