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问题 选择题
已知
a
=(1，-1)，
b
=(2，3)，则2
a
+
b
=（　　）
A．（4，1）B．（1，4）C．（4，2）D．（2，-2）
答案

2

a
+
b
=2（1，-1）+（2，3）=（2×1+2，2×（-1）+3）=（4，1）

故选A．

单项选择题

对手的消毒效果进行监测时，被检人五指并拢，用浸有含相应中和剂的无菌洗脱液棉拭子在双手指屈面从指根到指端（）。

A、涂擦一次

B、涂擦两次

C、往返涂擦两次

D、往返涂擦三次
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单项选择题

Most people have no idea of the hard work. One of the questions that is always asked of me is (1) I became an animal collector in the first (2) .The answer is that I have always been interested in animals and zoos. According to my parents, the first word I was able to say with any (3) was not the conventional "mamma" or "daddy", (4) the word "zoo", which I would (5) over and over again with a shrill (6) until someone, in order to (7) me up, would take me to the zoo. When I (8) a little older, we lived in Greece and I had a great (9) of pets, ranging from owls to seahorses, and I spent all my spare time (10) the countryside in search of fresh specimens to (11) to my collection of pets.(12) on I went for a year to the City Zoo, as a student (13) , to get experience of the large animals, such as lions, bears, bison and ostriches, (14) were not easy to keep at home. When I left, I (15) had enough money of my own to be able to (16) my first trip and I have been going (17) ever since then. Though a collector’s job is not an easy one and is full of (18) , it is certainly a job which will appeal (19) all those who love animals and(20) .

第（3）空应选择（）

A．clarity

B．emotion

C．sentiment

D．affection
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