问题
单项选择题
若轴的转速低于60r/min时，应用润滑脂将整个轴承室充（）。
A.2／3
B.1／2
C.100％
D.1／3
答案
参考答案：C
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若轴的转速低于60r/min时，应用润滑脂将整个轴承室充（）。
A.2／3
B.1／2
C.100％
D.1／3
参考答案：C
| 完形填空。 | ||||
| When I was a boy of twelve, something stopped me forever from putting any wild creatures in a cage. We lived in a village. Every evening the mockingbirds (仿声鸟) would come and 1 in the trees and sing. No musical instruments can produce a more 2 sound than the songs of the mockingbird. I decided to 3 a young bird and keep it in a cage so that I would have my own private 4 . Finally I managed to catch 5 and put it in a cage. At first, the bird moved wildly about in the cage, but at last it 6 in its new home. I felt very pleased 7 myself and looked forward to some beautiful 8 from my little musician. On the second day, my new pet's 9 flew to the cage with something in her mouth. the baby bird 10 everything she brought to it. I was pleased to see this. 11 , the mothe r knew better than I about how to 12 her baby. the following morning 13 I went to see how my bird was doing, I was shocked to find it on the floor of the cage, 14 I had taken good care of it, but 15 had happened? Arthur Wayne, a famous scientist, happened to be visiting my fathe r at the time. Hearing me crying over the death of my bird, he 16 what had happened."A mothe r mockingbird, finding her young in a cage, will sometimes bring it 17 food. She thinks it better for her young to 18 than to live in a cage." 19 the n I have never caught any living creature and put it in a cage. All living creatures have a 20 to live free. | ||||
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