题干
--The plane is due to take off at 7∶50 from the airport.
--________ we fail to arrive there in time?
--________ we fail to arrive there in time?
A：What if
B：As if
C：Even if
D：Only if
答案(点此获取答案解析）
A
2B(g)+E(g) △H>0, 达到平衡时，要使正反应速率降低，A的浓度增大，应采取的措施是