---- I was warned to keep quiet about the case on court unless _______.---- So you mean you will do everything _______ then?
_______ has recently been done to provide more buses for the people, a shortage of public vehicles remains a serious problem.
There are many other examples _______ the development of Chinese writing.
Listen! His family must be quarrelling, _______?
More than one _______ the people heart and soul.
This problem may lead to more serious ones if _______ unsolved.