问题
单项选择题
关于钛合金的切削加工性很差原因说法正确是（）。
A.钛合金化学性能不活泼
B.导热系数较大
C.加工表面有硬而脆外皮，给第二次走刀带来困难
D.切削温度低
答案
参考答案：C
搜题请搜索小程序“爱下问搜题”
关于钛合金的切削加工性很差原因说法正确是（）。
A.钛合金化学性能不活泼
B.导热系数较大
C.加工表面有硬而脆外皮，给第二次走刀带来困难
D.切削温度低
参考答案：C
| 完形填空 | ||||
| The seasons in Australia are the opposite of ours. 1 it is winter here, it is summer there. Australia is 2 the south of the world. July and August are the winter months. The summer is in December, _ 3 and February. The north of the country is 4 than the south. Australia' s main problem is water. A 5 large part of the country has no rain at all. But east coast has the rain _6 the year round. There are no dry months here. In March 1982, there was a terrible drought in Australia. The summer rain didn't 7 . There were 138 million sheep in Australia this year. This was 14% of all the sheep in the world, Because there was no 8 rain, the grass didn't grow well, the farmers 9 to sell many of their sheep and many sheep 10 , too. It was a great disaster for Australia farmers.
|