21.______ is known to everybody , the moon travels round the earth once every month .
A It B As C That D What
22 The local government has decided to provide more job opportunities for college graduates ,________, in my opinion ,will benefit those who are still unemployed .
A what B that C where D which
23 John received an invitation to dinner , and with his work ________he gladly accepted it .
A finished B finishing C having finished D was finished