21. My dream is to study abroad in _______ European country after I finish my middle school.
A. a B. an C. the D. 不填
22. It’s really kind _______ them to work in their spare time.
A. of B. to C. for D. at
23. The dragon boat race was held on that day. _______ people watched it excitedly near the river side.
A. Thousand B. Thousands C. Thousand of D. Thousands of