题干
What a pity! I missed meeting my friend at the airport because my car was _____ in the traffic jam．
A：broken u
B：held u
C：kept back
D：kept u
答案(点此获取答案解析）
B
A：broken u
B：held u
C：kept back
D：kept u
CO ( g) + H2 (g)在一可变容积的密闭容器中进行，下列条件的改变对其反应速率几乎无影响的是（ ）
