Name: Martin

From: London

Class: Class 2, Mr Smith's class

Favourite animal: dogs

I've got a black dog and I do sports with it near my home.

Name: Lisa

From: New York

Class: Class 1, Mrs King's class

Favourite animal: cats

I've got a brown cat and I play with it at home.

Name: Lu Jin

From: Hangzhou

Class: Class 3, Mr Wang's class

Favourite animal: tigers

I've got many tiger pictures and there are two pictures on the wall.

Name: Song Yuan

From: Haikou

Class: Class 4, Mrs Li's class

Favourite animal: pandas

I've got many panda pictures and I go to see pandas in the zoo on Saturday.

“市场经济不等于资本主义，社会主义也有市场。”明确指出我国经济体制改革目标是建立社会主义市场经济体制的是

探究题

小明想设计一个探究金鱼藻在光下能否产生氧气的实验．他通过查资料知道：氧气很

少溶于水且具有助燃性，即能使带火星的木条复燃．为此，他设计了一个探究方案如下，请

将实验正确步骤，用字母表示出来：

A、把金鱼藻放在烧杯里，再将漏斗和试管依次反扣

B、将收集到一定量气体的试管取出

C、把装置移到光下

D、把带火星的木条插进试管

该实验的正确顺序是：____→____→____→____．

设向量$\overrightarrow{a}$=（cosα，sinα），$\overrightarrow{b}$=（cosβ，sinβ），其中0＜α＜β＜π，若|2$\overrightarrow{a}$+$\overrightarrow{b}$|=|$\overrightarrow{a}$﹣2$\overrightarrow{b}$|，则β﹣α等于（　　）