Two middle-aged passengers fell into the sea. ______, neither of them could swim.

(2013·福建泉州七中模拟)Whatever background you come from, you can be ________ successful with your hard work like many others.

If we leave right away,____ we’ll arrive on time.

They all looked ____ at the master and felt quite _____．

As is known to all language learners, the newly learnt words will soon be forgotten unless ______ used in everyday communication.