北斗二号卫星导航系统空间段将由()颗静止轨道卫星和()颗非静止轨道卫星组成。 ["5,21","5,30","3,21","3,30"]
6000步活动当量的涵义?
对预防感冒具有特殊的锻炼方法是()。 ["晨跑","游泳","自然力锻炼","登山运动"]
扶梯支承预埋铁应为厚度(),宽度≥200mm的低碳钢,长度符合厂家设计要求 ["≥10mm","≥15mm","≥20mm","≥25mm"]
维护手册中,风挡玻璃更换和测试的ATA章节是:() ["风挡的更换在ATA56章,风挡的测试在ATA30章","风挡的更换及测试在ATA30章","风挡的更换及测试在ATA56章","以上答案均不正确。"]
“四五”普法的对象有哪些?