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问题 填空题

一颗中子星的质量大约与太阳质量相等，为2× 1030 kg，但是它的半径才不过10 km，此中子星表面的重力加速度为____________；贴近中子星表面，沿圆轨道运动的小卫星的速度为______________．

答案

1. 33×1012m/s2；1.15×108 m/s

填空题

商务领航定制网关具有（），客户可针对不同部门设置不同的（）标识，设置不同的访问权限和安全机制。
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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（17）空应选择（）

A．normally

B．regularly

C．usually

D．often
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