单选题 The ski resorts are usually crowded. There are many people ______ skiing.

【正确答案】 C
【答案解析】这是there be句型，不能再有第二个谓语，排除选项A和D。Enjoy doing sth，enjoy后跟动词的-ing形式，want to do sth，want后跟动词不定式。定语从句在说明人时用who。选项C是正确的。