Yang Liwei spent the whole evening talking about the things and persons ________ none of us has ever heard of in CCTV station

Last night I____ a book at home.

Full use should be _______the natural resources to combat the energy crisis.

Scientists say it may be five years ______ it is possible to test this medicine on human patients

1—Will Liu Xiang win in2012 Olympics—It ________his training.