49.It is high time that the international community ()together to fight against terrorism.

45.I’m sure that reserves of coal here are ()to last for at least of half a century.

44.He has made it clear ()he will never go back on his word.

43.What John said just now had little to do with the question ()discussion.

42.The man tried to force the locked door open but ().

41.Andrew’s sun-tanned face is a suggestion that he ()in excellent health.

40.His efforts to develop new energy sources ()to be rewarding.

39.The robot “teacher” was talking with his students as though it ()a human teacher.

38.Tom never dreams of ()for him to study abroad in China so soon.

37.Tom returned to his house after a holiday， only to find it ().

36.The reason ()he gives for not coming is that his mother won’t let him.