He advised the fanners to choose the best seed-heads,____ that had the best colour.
Four Chinese models were ________ the 14 people awarded prizes on Friday at the World Supermodel Competition.(2009·上海)
It's not easy to change habits,________ with awareness and self-control,it is possible.
There's no way of knowing why one man makes an important discovery________another man,also intelligent,fails.
It was a real race________time to get the project done.Luckily,we made it.
A serious study of physics is impossible________some knowledge of mathematics.