The water behind the Three Gorges Dams (三峡大坝) should be ______ higher than downstream(下游)。
______ road out of town is good, but this one is better than the other.
Quancheng Square is one of _____ largest in China, _____ second to Tiananmen Square.
It was _______ he came back from Africa that year ________ he met the girl he would like to marry.
Roses need special care ______ they can live through winter.
Sam _____ some knowledge of the computer just by watching others working on it.