题目内容：

Miss Chen is playing the piano.(对 piaying the piano 进行提问
答案是what does Miss Chen doing?
还是what is Miss Chen doing

优质解答

What is Miss Chen doing?

追问：

为什么 what can you do? 为什么选择be动词

追答：

be doing sth 现在进行时，正在做某事，问句 Is/Are sb doing sth? do sth 一般现在时，常常做某事，问句 Does/Do sb do sth?