—Alice，you are supposed________ part in
the party in time.
—Sorry，but I had an unexpected visitor.
A．to take B．to have taken
C．to be taking D．taking
—Alice，you are supposed________ part in the party in time.
—Sorry，but I had an unexpected visitor.
A．to take B．to have taken
C．to be taking D．taking
B [由下句可知，上句意：你理应及时参加晚会(但事实上没参加)；was/were supposed to do表示“本应该发生但实际未发生的事”，相当于be supposed to have done。]