- 搜標(biāo)題
- 搜題干
- 搜選項(xiàng)
單項(xiàng)選擇題
發(fā)動機(jī)每次啟動不應(yīng)超過（）秒。
A.10s
B.20s
C.30s
D.40s
A.10s
B.20s
C.30s
D.40s
