焊接面罩的作用是防御焊接产生的紫外线、红外线、强可见光、金属火花等对（）的伤害。
A.头部
B.呼吸道
C.眼睛和面部
参考答案：C
You can use a larger plastic bottle, ____ is cut off, ____ as a pot to grow flowers in.
A．of which the top; with it’s top
B．whose top; with its top
C．whose top; the top of it
D．the top of which; with it’s top
主机跳闸靠哪几只电磁阀？
