21. When Tom invited his friends to see his flat by ____ sea, they agreed immediately without _______ second thought .
A. \ ; \ B. \ ; a C. the ; the D. the ; a
22．Although I try to talk to my classmates, I still find _______ hard to make good friends with them.
A. them B. they C. it D its
23．The people of the city of Tangshan thought little of these strange events and went to sleep _________ that night .
A. as a result B as a matte of fact C as well D as usual
