问题描述：
请说明原因,
My pen pal Andrew found it difficult _____Chinese well.
a.learning b.learn c.to learn d.learned.
我觉得答案应该是c,可标准答案是a,为什么?
My pen pal Andrew found it difficult _____Chinese well.
a.learning b.learn c.to learn d.learned.
我觉得答案应该是c,可标准答案是a,为什么?
问题解答：
我来补答展开全文阅读