问题描述：
will you please show me how to operate the new machine?
sure.it is a piece of cake ,now let me tell you（ ）to do first.
A what B how Cwhether Dwhen
选什么.
是A 还是B
为什么？
sure.it is a piece of cake ,now let me tell you（ ）to do first.
A what B how Cwhether Dwhen
选什么.
是A 还是B
为什么？
问题解答：
我来补答展开全文阅读