________ is known to us, May 12, 2008 was the day _______ Wenchuan earthquake happened.
He made another wonderful discovery, _____ of great importance to science.
As I know,there is _____ car in this neighborhood.
_____,success results from hard work.
_____ the general state of his health,it may take him a while to recover from the operation.
Helen was much kinder to her youngest son than to the others, _____,of course,made the others envy him.