單項(xiàng)選擇題

Bolts, nuts, split pins, hinges, wheels and stoppers should be frequently （）.

A.checked
B.closed
C.removed
D.cleared

你可能感興趣的試題

單項(xiàng)選擇題

Before opening and closing the hatches, the spaces around the covers, all the parts and the gears should be （）.

A.cleared
B.checked
C.removed
D.repaired

單項(xiàng)選擇題

The foreman said three （）would come on board to load cargo.

A.teams
B.parties
C.gangs
D.pairs