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问题 选择题

我国研制成功一种相对原子质量为18，质子数为8的氧原子构成的双原子分子气体，下列说法正确的是  （　　）

A．这种原子的核外不一定有8个电子

B．这种气体的相对分子质量为36

C．这种气体中氧元素的化合价不为零

D．这种原子和氢原子构成水分子的相对质量为18

答案

A、根据核内质子数=核外电子数，故这种原子的核外一定有8个电子，故A错误；

B、因为“相对原子质量为18，质子数为8的氧原子构成的双原子分子气体”，则这种气体的相对分子质量为36，故B正确；

C、此氧原子构成的双原子分子气体为单质，其化合价一定为零，故C错误；

D、这种原子和氢原子构成水分子的相对分子质量为18+2×1=20，故D错误．

故选B．

完形填空

阅读表达 阅读短文，按要求完成短文后的各项任务。

Dragon –Boat Festival is also called the DuanWu Festival. (1)It is celebrated on the _____day of _____ according to the Chinese calendar．Here is something about Dragon-Boat Festival.

For thousands of years, the festival has been marked by eating Zong Zi and racing dragon boats .People hold the dragon-boat races in order to remember Qu Yuan , one of the greatest poets(诗人)in China．

Qu Yuan was born in Zigui of Hubei Province over 2,200 years ago．Qu Yuan was an honest minister(大臣)of the State of Chu，during the Warring States Period(475-22 l BC)(战国时期)．He was upright and wise. He wanted to bring his country peace and make the country stronger, but the country was in the hands of bad officials，he failed．At last，he was very discouraged. He ended his life by throwing himself into the Miluo River. It was said that people jumped from boats into the river and tried to save him. But it was too late. They were very sad. They threw rice into the water to feed Qu Yuan’s spirit.

(2)Now we read his poem Li Sao which was full of deep love for his country．We can see the dragon-boat races and have a kind of Chinese food named Zong Zi to eat during the Dragon-boat Festival．

小题1:在（1）句的空白处填入合适的词，使上下文完整。_____  _____

小题2:Why do we hold the dragon-boat races? _________________________________.

小题3:把(2) 处划线部分译成汉语。

________________________________________________________

小题4:在文中找出与下列句子意思相近的句子：He jumped into the Miluo River and died.  ________________________________________

小题5:找出或写出文章中最能表达该文中心的句子。

________________________________________________________
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单项选择题

Rh血型型抗原有（）。

A.40多个

B.50个

C.20个

D.10个

E.5个
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