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问题 选择题

二氟甲烷是性能优异的环保产品，它可替代某些会破坏臭氧层的“氟里昂”产品，用作空调、冰箱和冷冻库等中的致冷剂。试判断二氟甲烷的结构简式[ ]

A． 有4种

B． 有3种

C． 有2种

D． 只有1种

答案

答案：D

单项选择题

海马损丧表现出的记忆障碍是（）.

A.瞬时性遗忘

B.逆行性遗忘

C.顺行性遗忘

D.反应性遗忘
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单项选择题

Sometimes we have specific problems with our mother; sometimes, life with her can just be hard work. If there are difficulties in your (1) , it’s best to deal with them, (2) remember that any (3) should be done (4) person or by letter. The telephone is not a good (5) because it is too easy (6) either side to (7) the conversation.

Explain to her (8) you find difficult in your relationship and then (9) some new arrangements that you think would establish a (10) balance between you. Sometimes we hold (11) from establishing such boundaries because we are afraid that doing (12) implies we are (13) her. We need to remember that being (14) from our mother does not (15) mean that we no longer love her. If the conflict is (16) and you cannot find a way to (17) it, you might decide to give up your relationship with your mother for a while. Some of my patients had (18) "trial separations". The (19) allowed things to simmer down, enabling (20) .

14（）

A.harmonious

B.wholesome

C.malignant

D.independent
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