通信电源为什么要接地线？其作用？
《八十天环游地球》中福格未在旅途中使用过（）。 ["大象","雪橇","轮船","自行车"]
风管制作安装的工程量如何计算？
“文明交通行动计划”是由哪两个部委联合发文？从何时开始正式启动实施？计划实施多长时间？
If，by refusing to name a place of discharge，the Charterer prevents the Shipowner from earning freight，（）will have to pay it as damages for breach of contract. ["she","he","it","they"]
气泡病原因是什么？
