4,(-) Liz didn't enjoy her summer vacation last year
( ? ) Did Liz enjoy her summer vacation last year?
5,(-) Nam won't be absent from school tomorrow.
( ? ) Will Nam be absent from tomorrow?
6, (-)She doesn't go to the gym twice a week.
( ? ) Does she go to the gym twice a week?
7,(-) My brother hasn't ever spent his summer holiday in England.
( ? ) Has your brother ever spent his summer holiday in England?