求英语大神来把这五个句子改成特殊疑问句

Maria has been studying English since 1999.
How long has Maria been studying English?
My cousin has been playing football for muchly 4 years.
How long has your cousin been playing football?
Alison has been skating for the whole 5 hours.
How long has Alison been skating
We have been waiting here for the whole 3 hours.
How long have you been waiting here?
Bill has been doing homework since he came back.
How long has Bill been doing homework?全是How long吗... 我英语有点白痴。你的题目并没给出做题的限制条件，这五句都是延续一段时间的现在完成时的句子。要改成特殊问句，也只有对时间状语提问最合适了。