London Olympic Games Badminton Men’s singles final, Lin Dan won the gold medal, becoming the first____________ the championship

For some time the expert __________ people of the health risks caused by passive smokingHe says he won’t stop until all the smokers around him decide to quit smoking

Scientists are convinced___the positiveeffect of laughter___physical and mental health.

I’m frustrated after so many failures. I can’t see any hope.– Behind every misfortune _____!

Mum,I volunteer my time the plates.