【单选题】能够在水平方向自由转动的磁针,它静止时总是指向南北方向,这是由于( )
【单选题】下列说法正确的是( )
A.
指南针的南极总是指向南方,说明地球是一个大磁体
【多选题】常用粉末冶金结构材料主要有( )材料,主要用于制造机械零件、含油轴承、制动摩擦片等。
【简答题】Scientists had ( 寻找 ) for a solution to the mystery, but they didn't find it. 2 . On reaching the station, the passenger found someone in rags ( 游荡 ) around the station. 3 . There are a lot of ( 过错 ) ...
【单选题】The tourists took a keen _____ in the guide ’ s description of the region.
【简答题】(在用设备)达到以下三个条件者为完好设备:①设备()良好,如动力设备的出力达到原设计标准,机械设备精度能满足生产工艺要求,运转无超温、超压现象;②设备运转正常,零部件齐全,没有较大缺陷,腐损腐蚀程度不超过规定的技术(),主要的计量仪器、仪表和润滑系统正常;③原材料、燃料、油料等()正常,基本没有漏油、漏气(汽)、漏电现象,外表清洁、整齐。
【简答题】Sydney's Harbour Bridge, one of 1________ most famous bridges in the world, towers over Australia's largest city. 2_________ (climb) the bridge is not a crazy thing to do 3 _______ tourists started cl...