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问题 选择题

为了治理废水中Cr2O72-的污染，常先加入试剂使之变为Cr3+，该试剂为 [ ]

A．NaOH溶液

B．FeCl3溶液

C．明矾

D．Na2SO3和H2SO4

答案

答案：D

听力题

根据短文内容和所给汉语提示，写出短文空白处各单词的正确形式。（每空限填一词）

I’m Du Yufan. I’m in Class One, Grade Seven at Dashan school. My school is not   小题1: (大的). You can see   小题2: （仅仅）three classrooms in it. Look, this is my classroom. You can see two students   小题3:  (和) a teacher. The   小题4:  (男孩) is Li Donghui. He is eleven years old. The girl is Tang Xiaolu. She is   小题5:  (十二) years old. It’s one o’clock in the ­­­­小题6:  (下午). They have  小题7: （午饭）in the classroom. Li Donghui likes vegetables. He eats some   小题8: （西红柿）. Tang Xiaolu likes fruit. She eats an 小题9:  (苹果). But where is the teacher? Oh, she eats rice at the teacher’s   小题10:  (书桌). They are very happy.
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判断题

搭拆脚手架时，地面应设围栏和警戒标志，并派专人看守，严禁非操作人员入内。（）
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