she failed the exam=she failed in the exam 或she not passed the exam
my mother is a dancer 这个也是找同义句?你记错题了吧 是问句装换的吧?!
it takes me half an hour to walk there
=it takes me 30 minutes to walk there
= I spend halk an hour to walk there（there是地点副词 前面不能加动词不定式!）