回答下列问题：
（1）构成原子的粒子有____ 、____ 和____ ；整个原子不显电性的原因是____ 。
（2）构成物质的微观粒子有____ 、____ 和____等。例如：构成氧气的粒子是____ 、构成铁的粒子是____ 、构成氯化钠的粒子是____ 和____ 。
（3）下列物质：①氧气；②人体呼出的气体；③液氧；④空气中0.03%的稀有气体；⑤二氧化碳；⑥洁净的空气。其中属于纯净物的是____ ；请选出一种混合物并说明其中的成分____ 。

想一想，猜地名。

①拆信。 （打一河南地名）____

②两个胖子睡一起。（打一安徽地名）____

③向日葵。（打一北京区名）____

下列说法正确的是（     ）

    Look at the girl. Her name is Lucy. And this lovely girl is her twin sister Lily.1parents are both （两者都）teachers. They work hard.

    Lucy and Lily2at No.4 Middle School. They go to school3Monday to Friday. They have no classes on Saturdays and Sundays. They have breakfast at 6:30. They go to school at 7:00. Classes

    4at eight. They have four5in the morning and three in the afternoon. They have6at 12: 15. At 3:50,they have sports.

    Lucy and Lily study Chinese, math, English, geography, physics, history and other lessons. Lucy's favorite7is music,8it's relaxing. Lily likes science best. She thinks it's difficult 9interesting.

    Their parents like reading. They often read books at home. Their parents are strict(严厉地)with  them, but sometimes they are very kind and friendly to their children. Lucy and Lily love their10 very much.