题干
—________ did you stay there?
—I stayed there for two hours.
A：How soon
B：How far
C：How long
D：How often
答案(点此获取答案解析）
C
—________ did you stay there?
—I stayed there for two hours.
A：How soon
B：How far
C：How long
D：How often
CO(g) + H2(g) △H>0，既要提高反应速率又要提高H2O的转化率，下列措施中可行的是 ( )