单项选择题
We prefer all the spare parts （） on board before departure.
A.to send B.to be sent C.for being sent D.being to send
单项选择题 It is well known that the whole power distribution of the ship’s electrical services mainly depend on the（）.
单项选择题 How do you treat someone suffering from electrical shock after you secure the source?（）
单项选择题 Tools with （）handles should be used to check electric circuit.
