Teachers        be sensitive to the development level of each student so as to help them better.

He _____ have completed his work; otherwise, he wouldn’t be enjoying himself by the seaside．

 He ________ to the cinema last night, for he stayed with me.

 —I think the man over there must be Bob.—It ______ be him. He has gone to Paris.

E-Commerce ______ mislead customers at times even though it's more convenient and faster in general.