电机车喇叭宏亮，音响有效距离大于（）。
A.20M
B.30M
C.40M
D.50M
参考答案：C
请你用形容词描绘以下图画。
1. It's easy for him.
It's ____ for the boy.
2. It's ____ for ____ .
It's ____ for ____ .
3. It's ____ for ____.
It's ____ for ____.
4. It's ____ for ____.
电渣压力焊有哪些阶段？
