---What is that? Is it an English learning machine?---Yes. It us to improve our English.A

问题补充：

---What is that? Is it an English learning machine?

---Yes. It us to improve our English.

A. is used for helping B. used to help C. used to helping

答案：

解析：考察、used 用法。be used for doing sth表示用来做某事。Used to do sth过去常常做某事；used to sth习惯于某事。句意：那是什么？是一部英语学习机吗?是的，它是被用来帮助我们提高英语的。故选A。