—Everyone in my class passed the exam.—Oh, really? It ________ difficult.

--- _________ David be the new chairperson of the Students’ Union? --- He ________ be, but I’m not sure.

—What have you learned from your experience in Thailand?—Well, meeting people from another culture ______ be very difficult．

．Just be patient. You ________expect the world to change so soon.

—Who is speaking there? —It        be Uncle Li. He has gone to Shanghai.