对下列句子中的划线部分进行提问,每空一词(含缩略形式).

问题描述:

对下列句子中的划线部分进行提问,每空一词(含缩略形式).
3.My last name is Zhang.用Zhang提问
_________ _________ last name?
4.His telephone number is 231-9878.用231-9878提问
__________ __________ his telephone number?

3.what's your last name
4.what is his telephone number