Scientists are convinced___the positiveeffect of laughter___physical and mental health.

___ the deaf children, theyoung lady has little time to care for her own daughter.

Urban Chinese travelled to 68 countries during the Spring Festival holiday, ________ an average of 6,000 yuan each.

__________ you say, we don’t believe you.

I wonder if you could go with me to the supermarket.—Sorry. I _______ my experiment report all the morningand haven’t finished yet.