题干
They feel ____(内疚) about not being able to see their son often because they are busy with their work.
答案(点此获取答案解析）
guilty
They feel ____(内疚) about not being able to see their son often because they are busy with their work.
有多种同分异构体，其中属于酯且苯环上有2个取代基的同分异构体共有
