题目

在下列物质①自来水 ②过氧化氢③五氧化二磷 ④空气中  含有氧分子的是_______（填序号，下同），属于纯净物的是______________。 答案：1）①④    ②③    We are middle school students．We’re in Class 3，Grade 1．This is our classroom．It is a nice big room．You can see a clock over the blackboard．You can see desks and chairs in the room．They’re new．The books are on the desks．The bags are behind the chairs．Can you see a big desk? It is the teacher’s desk．On the teacher’s desk you can see flowers．They are for our teacher, Miss Gao．She is a good teacher． 阅读短文，判断正（T）误（F）． 1．We are students．We’re in Class 1，Grade 3． 2．The books are on the desk and the bags are behind the chairs． 3．A clock is under the blackboard． 4．The teacher’s desk is big． 5．Miss Gao is a good teacher．