— Look, it _____ be Jack who is at the gate of the library.It _____ be him. He has gone abroad.may; must B. must; mayn’t C. must; can’t D. can; mayn’t
Many countries are increasing their use of natural gas , wind and other forms of ______.
The fact that many college graduates get lower pay than some workers has ______ a heated discussion.
I have no idea ______ it is that makes him puzzled.
He sat at the desk, __________ a novel.
______ tourism developing, more and more people prefer to go travelling for a holiday.