题目

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 fa下列有关环境问题的说法中正确的是                                         (      )A．空气质量报告的各项指标中，有二氧化硫、二氧化氮和二氧化碳的指数B．pH在5.6～7.0之间的降水可通常称为酸雨C．含氮、磷合成洗涤剂可以被细菌分解，故不会导致水体污染D．汽车尾气中氮氧化物、一氧化碳、碳氢化合物和颗粒物等，严重污染大气