21. ______ world’s largest retailer, Wal-Mart, has opened its _____ third store in Beijing, which means the firm now has 52 stores in China.
A. The; a B. A; a C. The; the D. The; /
22. — Isn’t it hard to drive downtown to work?
—Yeah, that’s why I ______ to work by train.
A. have gone B. have been going C. was going D.will have gone
