题干
Barack Obama has taken personal blame ________ the security failures which led ________ the attempt to blow up a plane on Christmas Day.
A：of; to
B：for; to
C：on; o
D：in; o
答案(点此获取答案解析）
B
2CO（g）△H>0。该反应达到平衡后，下列条件有利于反应向正方向进行的是（ ）