在做晶体的熔化实验时，小明提出“晶体的熔点与晶体是否纯净有没有关系？”。为了研究解决这一问题，小明做了如下实验：将水和少量酒精混合后放入冰箱的冷冻室，每隔2分钟用温度计测一次混合物的温度，并观察其状态，实验记录如下：

时间（分钟）

0

2

4

6

8

10

12

14

16

18

20

22

温度（℃）

4

2

0

－2

－4

－6

－6

－6

－6

－6

－6

－8

状态

液

液

液

液

液

液

液固

液固

液固

液固

固

固

植物体细胞在生长过程中，液泡的变化是（）

下列四城市中，地球自转线速度最大的是                

—_____?

—She's in her school.

       Shenzhou X and three astronauts(宇航员) were sent up from Jiuquan Satellite Launch Center, Gansu province, into a clear blue sky on Tuesday, bringing the nation one step closer to building its own space(太空) station in 2020.
　　Two men, mission commander(指挥官) Nie Haisheng and Zhang Xiaoguang, and China’s second female astronaut, Wang Yaping, are expected to stay in space for 15 days.
　　They will teach young people about science and do two space dockings, between Shenzhou X and the unmanned Tiangong-1 space module, a technically difficult procedure that brings two spaceship together in high-speed orbit(轨道).
　　The trip is our country's fifth manned space mission, 10 years after the country’s first astronaut, Yang Liwei, went into space in 2003.