21．A couple of cars crashed at _____ crossroads a few metres away from _____ shop.
A. a…a B. /….a C.. /…the D. the…/
22. –I like your new sunglasses!
–Thanks. I had to try on almost a dozen pairs ____I decided to get them.
A. as B. when C. after D. before
23. While listening to English materials, fix your mind on what is really important, or you will _____remembering nothing.
A. end up B. take up C. lead to D. stick to
