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【简答题】
阅读理解。 Air is all around us. At the time we are born, air is around us everywhere (到处). We live in air. All living things need air. Living things cannot live without air. We can go without food or water for a few days, but we can't live a few minutes without air. We take in air. When we are working, we need more air. When we are sleeping, we need less air. We live in air but we cannot see it. We can only feel it. We can feel it when it is moving. Moving air is called wind. How can you make air move? Here is one way. Take an open book in your hands in front of your face. Close it quickly. What can you feel? It is air. 1. Where is air? A. It's on the table. B. It's around us everywhere. C. It's near us. D. It's not here. 2. Moving air is called _______. A. wind B. rain C. snow D. cloud 3. When do we need more air? A. Sleeping. B. Sitting. C. Working. D. Standing.
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参考答案:
举一反三
【简答题】根据某些条件对一个关系作水平分解,选择符合条件的元组组成一个新的关系,这样的操作称为( )。 A)投影 B)选择 C)等值连接 D)自然连接
【单选题】根据某些条件对一个关系作水平分解,选择符合条件的元组组成一个新的关系,这样的操作称为
A.
投影
B.
选择
C.
连接
D.
自然连接
【单选题】听力原文:W: Michael, would you like to eat out tonight? M: Oh, I'd really like to, but I have promised my sister to see a movie with her tonight. Q: What will the man do this evening? (4)
A.
To visit his sister.
B.
To eat out with the woman.
C.
To see a movie with his sister.
D.
To eat out with his sister.
【单选题】氨茶碱的平喘机制是
A.
激活腺苷酸环化酶
B.
抑制腺苷酸环化酶
C.
激活磷酸二酯酶
D.
抑制磷酸二酯酶
【单选题】— I like speaking better than listening in English learning. —Oh, really? I think you should be good at of them.
A.
both
B.
neither
C.
some
D.
all
【简答题】根据某些条件对一个关系作水平分解,选择符合条件的元组组成一个新的关系,这样的操作称为( )。 A)投影 B)选择 C)等值连接 D)自然连接
【单选题】–I am twelve and I like English. -- Oh, really? I am twelve and I like English.
A.
also; also
B.
too; too
C.
also; too
D.
too; also
【单选题】根据某些条件对一个关系作水平分解,选择符合条件的元组组成一个新的关系,这样的操作系称为
A.
投影
B.
选择
C.
连接
D.
自然连接
【单选题】氨茶碱的平喘机制是
A.
抑制细胞内钙释放 ;
B.
抑制 磷酸二酯酶 ;
C.
抑制磷酯酶 A2;
D.
激活腺苷酸环化酶 ;
E.
抑制鸟苷酸环化酶
【单选题】氨茶碱的平喘机制是
A.
抑制磷酸二酯酶
B.
激活磷酸二酯酶
C.
激活腺苷酸环化酶
D.
抑制鸟苷酸环化酶
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