下列现象或性质能体现钠的物理性质的是（　　）

①钠燃烧时发出黄色的火焰 ②钠燃烧时生成过氧化钠 ③熔点低 ④密度比水小⑤热和电的良导体 ⑥钠有很强的还原性．

    Now I'm in a new school. And I go to school from Monday to____ （周五）as usual . The new school is next to the Xin Hua Bookstore. There is a big park across from our school. And there are three buildings in our school—the ____ （学生的）building , the teachers’ building and a library building. My friends and I like ____ （阅读）in the library after school. The teachers in our school are very good and strict. And the students in our school work____ （努力）every day. Our schoolyard is very beautiful, like a garden. You can see ____ （很多）trees and flowers in it. If you come to our school ____ （从……）the airport, You can ____ （乘坐）a taxi and go down the highway. Go across the bridge and turn ____ （左边）then go straight along the New Bridge Street. Our school is about____ （三）hundred meters along on the right. It's ____ （容易）to find it. Welcome to our school!