- 搜標(biāo)題
- 搜題干
- 搜選項(xiàng)
單項(xiàng)選擇題
救生艇下水每隔三個(gè)月進(jìn)行一次。（）
A. Lifeboat launching is operated at intervals of three months.
B. Lifeboat launching is operated at intervals for three months.
C. Fire drill is carried out once a month.
D. Don’t operate two or more hatch covers at the same time.
