谁能帮我解答几道英语题？谢谢

.__B_he have apologized to Kate?
Yes,he___.Otherwise,she couldn't be dating with him now
a.must can b.can can c.must must have d.can must have
2.__D_is often the case,he succeeded in this exam again.
a.what b.so c.which d.as
3.__C_everything into account, the work is getting on well
a.take b.taken c.taking d.to take
4.They are discussing in the next room__B_will go to conference on behalf of the manager
a.whoever b.who c.what d.whoever
5.The man often feels lonely.He seems to have__B_most of his friends
a.fallen b.dropped c.stopped d.made