1.It was obvious that you didn't pay attention to my lecture.You____something else.

1.It was obvious that you didn't pay attention to my lecture.You____something else.
A.thought of B.have thought of C.were thinking of D.had thought of
2.The bear,a meat-eating land animal,is generally peaceable if ___ young are left undisturbed.
A.it and its B.it and it's C.it and their D.itself and their
3.There is a biologist at Boston University___ believes that insects developed wings in order to collect solar heat.
A.where B.which C.who D.whom
4.There is an old joke which involes two old friends arguing about who is being ___.
A.a more unfaithful B.most unfaithful C.the more unfaithful D.the most unfaithful