根据保护幼稚产业学说，经济发展处于下列哪一阶段的国家应实行保护贸易政策______。
A．
B．
C．
参考答案：B
A：Hello, Betty. What did you do last summer vacation?
B: I visited my uncle.
A: 小题1: .
B: They live in Dalian, a beautiful city.
A: 小题2: .
B: I stayed there for a week. 小题3: .
A: No, I haven’t. But I’m going to spend a holiday there.
B: You’d better go to Dalian in summer. So you can enjoy swimming in the sea..
A: 小题4: I will go there this summer vacation.
B: 小题5: .
A: By plane
为什么要规定变压器绕组的温升？国际上规定温升多少？
