—Is your brother going to Jack's birthday party tonight?

—I am not sure. He _____ go to the concert with his girlfriend instead. [ ]

A. ought to

B. has to

C. might

D. must

(8分)两个极易导热的材料做成的体积相等的容器A和B，A是密闭定容的，B带上下可移动的活塞(气体不渗漏).在等温下向A、B两容器中充入等物质的量的N₂O₄固体并使之迅速气化.

(1)在两容器内N₂O₄刚刚全部气化的时刻(温度相同)，两容器中出现的现象是___________________________________________.

(2)反应进行的某时刻t₁(s)时，两容器生成NO₂的速率A                   B(大于、小于、等于)，理由是                                                               .

(3)当两容器内都达到平衡时，N₂O₄的转化率A                   B(大于、小于、等于)，理由是                                                                                                                .