_________ no doubt that a green campus plays an important role in the growth of students, both physically and mentally.

Tom. Why do you look so tired? — Because I often study late ______ 10 o’clock at night.[ ]

Tom, do you know if Sam ________to my party next week?—I think she will come if she________ free.

When something ________ me, I can always go to my friends for help.

His son often ______with me after school.