按课文填空。根据课文内容填入适当的单词，完成短文。（10分） It’s also probably a good idea for parents to _76 teenagers to study in groups 77 the evening. I know we get 78 sometimes, but we 79 a lot from each other. We also think that vacations should be   80 . At present they’re too short. Longer vacations would give us time to do things 81 volunteering. Last summer I had an 82 to volunteer at the local hospital, but I couldn’t because I had to _84 back to school. It would be a good _84 for me because I want to be a doctor when I’m 85 .