货物列车每百吨列车重量的高摩合成闸瓦换算闸瓦压力不得低于()(87km/h)。
A.180kN
B.230kN
C.260kN
D.280kN
参考答案:A
Information has been put forward _____ more middle school graduates will be admitted to universities.
A.while
B.that
C.when
D.as
在如图所示的四种现象中,能体现“分子在不停息地运动”的是: