钛合金是高熔点金属,但也可以用相应的焊接方法进行()。
参考答案:熔化焊
情景选择。
1. 当你初次见到李明时,向他问好,你应说:[ ]
A. Nice to see you.
B. Nice to meet you.
2. 当你想知道别人的年龄时,你应说:[ ]
A. How old are you?
B. How are you?
3. 别人答十二岁,说: [ ]
A. I'm twelve.
B. I'm twelve years.
4. 你想问他是哪国人时,应说:[ ]
A. Where are you?
B. Where are you from?
5. 当你想把你的朋友介绍给李明时,说: [ ]
A. This is my friend.
B. He's my friend.
发动机排放机油的最佳状态为()
A.机油热态
B.机油冷态
C.油温在50~60℃时