21.Mr.White, who comes from ____ European country, has formed _____habit of attending ____ church on Sundays.
A.an; /; the B.a; a; a C.an; the; / D.a; the; /
22. I would appreciate ______, to be frank, if the goods could be delivered as soon as possible.
A.you B.that C.it D.myself
23.By the time he retires, professor Baker _____ for almost forty years.
A.will have taught B.had taught C.has taught D.is teaching