________ hard one may work, one cannot master a foreign language in a month or two.
Students ___________ remain in their seats until all the papers have been collected.
__________strong earthquake struck __________ Yaan, Sichuan province on April 20, 2013.
―Hey, you haven’t been acting like yourself. Everything is OK? ―_________.
In this company, it is required that anyone who ______ recently come here _____ this kind of test.
I can’t believe that there are _____ many poor people in ____ a rich country.