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问题 不定项选择题

某溶液由盐酸、碳酸钠溶液、稀硫酸、氯化铜溶液中的一种或几种混合形成，现向该混合溶液中滴入氢氧化钡溶液，产生沉淀的质量与加入氢氧化钡溶液体积的关系如图所示．则下列关于溶液中溶质的判断正确的是

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A．肯定没有碳酸钠

B．肯定有硫酸

C．是否含有氯化铜不能确定

D．至少含有硫酸或盐酸中的一种，也可能两种同时含有

答案

答案：A

单项选择题

Generally speaking, a British is widely regarded as a quiet, shy and conservative person who is (1) only among those with whom he is acquainted. When a stranger is at present, he often seems nervous, (2) embarrassed. You have to take a commuter train any morning or evening to (3) the truth of this. Serious-looking businessmen and women sit reading their newspapers or dozing in a corner; hardly anybody talks, since to do so would be considered quite offensive. (4) , there is an unwritten but clearly understood code of behavior which, (5) broken, makes the offender immediately the object of (6) .

It has been known as a fact that a British has a (7) for the discussion of their weather and that, if given a chance, he will talk about it (8) . Some people argue that it is because the British weather seldom (9) forecast and hence becomes a source of interest and (10) to everyone. This may be so. (11) a British cannot have much (12) in the weathermen, who, after promising fine, sunny weather for the following day, are often proved wrong (13) a cloud over the Atlantic brings rainy weather to all districts! The man in the street seems to be as accurate — or as inaccurate — as the weathermen in his (14) .

Foreigners may be surprised at the number of references (15) weather that the British make to each other in the course of a single day. Very often conversational greetings are (16) by comments on the weather. "Nice day, isn’t it" "Beautiful!" may well be heard instead of "Good morning, how are you" (17) the foreigner may consider this exaggerated and comic, it is worthwhile pointing out that it could be used to his advantage. (18) he wants to start a conversation with a British but is (19) to know where to begin, he could do well to mention the state of the weather. It is a safe subject which will (20) an answer from even the most reserved of the British.

17（）

A. Since

B. Although

C. However

D. Only if
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单项选择题

呕吐的基本病机是

A．肝气犯胃，胃气上逆

B．胃失和降，胃气上逆

C．食滞伤胃，胃失和降

D．外邪犯胃，胃失和降

E．脾胃受损，胃失润降
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