Try not to buy too many things from abroad _________ it may cost a lot of money to bring them back.

A．because

B．so

C．so that

D．Although

弧形闸门支铰检修步骤（）。

A、拆下锈死的滚轮，将轴与轴承涂上润滑油脂后清洗陈锈

B、没有注润滑油设施的可直接在轴表面油脂润滑

C、轴与轴承小于设计的间隙公差的允许范围时，应更换轴瓦

D、用油漆溶剂与人工敲铲相结合的办法，清除支铰袖与铰链各缝隙间的旧漆与污垢