---I’m tired.Shall we find a chair in the park?--Good idea!A. to sitB. to sit onC. sit

问题补充：

---I’m tired.Shall we find a chair in the park? ----Good idea!

A. to sit

B. to sit on

C. sitting

D. sit on

答案：

A. to sit

(答案→)B. to sit on

C. sitting

D. sit on

解析：这里用不定式用定语，因为后面有宾语，所以不及物动词sit后要接介词。