【多选题】中国国土面积辽阔,气候类型丰富,中国具有以下哪几种气候类型
【多选题】下列关于氢气气体的描述正确的是()。
A.
氢虽无毒,在生理上对人体是惰性的,但若空气中氢含量增高,将引起缺氧性窒息
C.
存放于通风良好的地点进行固定或气瓶柜、气瓶室中,并设有泄露报警装置,避免泄露缺氧
【简答题】在正弦交流电路中,设电阻的端电压【图片】,若电阻上的电流【图片】和电压【图片】取关联参考方向,则在下面几个关系式中,一定正确的是( )。A. B. C. D.
【单选题】Rock-climbing is a breathtaking activity, very popular nationwide among young people, ______ cooperation as well as courage plays an important role.
【简答题】If you have ever been rock climbing, then you will know that it is not a very easy sport. In fact you probably felt quite defeated when you first tried to do any serious climbing. Indoor and outdoor r...
【多选题】正弦交流电路中电阻的电流和电压的关系是()。
【单选题】Rock-climbing is a breathtaking activity, very popular nationwide among young people, ______ cooperation as well as courage plays an important role.