什么是子午卫星导航系统?
根据管式泵和杆式泵两种抽油泵的特点,()适合于气量较小的井使用。 ["A、两者均","B、两者均不","C、管式泵","D、杆式泵"]
下列作家属于明初的有() ["A.宋濂","B.袁宏道","C.归有光","D.茅坤"]
今天所能见到的宋元话本,主要有() ["A.说经","B.小说","C.说铁骑儿","D.讲史"]
机车检修人员熟练掌握工、卡、量具和计量仪表的正确使用方法是确保()修的必备条件。 ["A、按范围","B、按“机统—28”","C、按工艺","D、按状态"]
船用雷达的用途是什么?