- These problems are too hard to . Will you give me some advice?
- There are many ways. The most important is to have a careful plan.
A:hand out
B:work out
C:look out
D:break out
A
B
C
D
阳极
白
红
蓝
阴极
如图所示汽油机____ 冲程,该冲程工作时将____ 能转化为____ 能.