Tom ___downloaded a virus into his computer, hecan not open the file now．

Who is that man over there? _______ it be our teacher?—— No, it _______ not be our teacher. It _______ be Mr. Zhang.

y, it’s raining outside. Shall I give you aride— Thanks. ______.

When asked to explain he did to make his students so fascinated with his lessons the teacher paused and thought deeply.

China is larger than _____ in Africa.