There are _____ reasons for the great changes in the countryside. [ ]

China, ____ one of the great four countries with ancient civilizations, is best-known _______ its great development in all the fields over the years.

I’m happy that we’ve finally cleared up some problems.— ______.

Hardly ______ off the bus when ______an old friend who he hadn’t seen for years.

In the exam , the you are, themistakes you’ll make