根据句意及所给中文提示或英文解释，写出句中所缺单词。
51. As ▲ （年级）9 students, we should work harder for a bright future.
52. We can see the light in his room ▲ （通过）the window.
53. I don't think students should be ▲ （允许）to bring mobile phones to school.
54. I studied very hard last term, so I made great ▲ （进步）in the exam.
55. I hope we can make a ▲ (决定) today.
56. I received a present from my friend, but I didn’t a ▲ it.
57. Peter’s father is very ▲ (not free), so he does not have much time for his family.