Nuclear science should be developed to benefit people _____ harm them[ ]

. ________ when the boulders suddenly disappeared.

Every boy and every girl as well as some teachers who ___ to visit the museum _____required to be at the bus station at 6:30.

Can we fix a time for the party? —We can’t have the party________none of us have any classes

I think dragons are the _____ of China. Do you think so -I agree with you.