21. The education of _______young is always _______ hot and serious topic in modern society.
A. /; the B. a; the C. the; a D. the; /
22. This is the first time we a film in the cinema together as a family.
A see B had seen C saw D have seen
23. I request that you __________ the task on time.
A. finished B. should finish C. could finish D. would finish
