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问题 选择题

下列物体中，物体的重量最接近2.5N的物体可能是（　　）

A．一只老母鸡

B．一袋牛奶

C．一只鸡蛋

D．一只蚂蚁

答案

A、一只老母鸡的质量在2.5kg左右，受到的重力大约为2.5×10N/kg=25N．此选项不符合题意；

B、一袋牛奶的质量在250g=0.25kg左右，受到的重力为0.25kg×10N/kg=2.5N．此选项符合题意；

C、一只鸡蛋的质量在60g=0.06kg左右，受到的重力为0.06kg×10N/kg=0.6N．此选项不符合题意；

D、一只蚂蚁的质量在0.1g=1×10-4kg左右，受到的重力为1×10-4×10N/kg=1×10-3N．此选项不符合题意．

故选B．

填空题

根据短文内容和首字母的提示，把所缺单词完整地填写在短文后的横线上。

     Nowadays, it's common to keep dogs as pets. We can often see dogs' owners taking them for a walk.

But have you (1)h______ of taking penguins for a walk? Here (2)i______ a piece of news from Japan. In

Tokyo Zoo, penguins go out for a walk in line every day. It is said that this can make them happy and stop

them from being homesick (想家的). The penguins in the zoo didn't eat as (3)w______ as they did in South

Pole (南极) and they were (4)u______ to the keepers when they first got to the zoo, maybe they were not

used to the life in the zoo. So the zoo keepers (5)c______ up with this good idea. They just let them walk

as they did in South Pole. Now, all these penguins have become happy.

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多项选择题

合理利用外资必须坚持的重要原则是（）

A.维护国家主权和民族利益

B.考虑利用外资的规模

C.坚持重质量、重效益

D.健全涉外经济法

E.提高政策透明度
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