动名词和不定式做主语及非谓语动词做表语 1. __________ a language requires time and effort. A. Learn B. Learning C. To learn D. Being learned 2. It is not always easy __________ invitations. A. to refuse B. refusing C. to be refused D. being refused 3. __________ now seems impossibl...

时间:2024-12-23 15:53栏目:行业资料