试题分析：

【1】go on vacation去度假，此处询问哪里，用疑问词where，时态可用过去时或将来时，故此处为Where did you go on vacation?/ Where are you going on vacation?

【2】be good for对……有益，故此处为It is good for my health.

【3】twenty percent of the students百分之二十的学生，故此处为Twenty percent of the students don’t exercise.

【4】How often多久一次，learn English学习英语；故此处为How often do you learn English?

【5】go to the movies去看电影，once a month一个月一次，故此处为I go to the movies maybe once a month.