You can only be sure of_____you have at present;you cannot be sure of something_____you might get in the future.()
The visiting Minister expressed his satisfaction with the talks, _______ that he had enjoyed his stay here.
"We must keep a secret of the things _______ here", the general said, _______ at the man in charge of the information office.
.China is one of the largest countries in the world, _______ 9.6 million square (平方) kilometers.
The old sick lady entered the hospital, ______ her two sons.
_______ many times, he still couldn't understand.