One of the difficulties we haveEnglish is how to remember new words and expressions. A. to

问题补充：

One of the difficulties we haveEnglish is how to remember new words and expressions.

A. to learn

B. in learning

C. learn

D. learned

答案：

A. to learn

(答案→)B. in learning

C. learn

D. learned

解析：句意：我们在学习英语中的困难之一是如何记住新单词和表达方式。Have difficulty in doing sth做某事有困难。结合语境可知选B。