英语题一道(用动词正确形式填空,可以加助动词或情态动词)

题目

英语题一道(用动词正确形式填空,可以加助动词或情态动词)
The worst thing about learning English is to forget something you've just lrarned,but ______(not give) up.

答案

not to give
but 是个介词 做转折
(The worest thing about learning English)主语 is to do sth. but not to do sth.
前面是to do 后面也应该是to do 保持句式前后一致