21. The visitors here are greatly impressed by the fact that _______ people from all walks of life are working hard for _____ new Chengdu.
A.不填; a B. 不填;the C. the; a D. the; the
22. This camera is of good quality. If it ______ break down within the first year, we would repair it at our expense.
A. would B. should C. could D. might
