已知：①A、B、C、D能与NaHCO₃反应；

②只有A、C能与FeCl₃溶液发生显色发应，且核磁共振氢谱显示苯环上有两种不同化学环境的氢原子．

③H能使溴水褪色且不含有甲基．

④F能发生银镜反应．

D能发生如下变化：

已知向量a,b夹角为${45}^{\mathrm{°}}$,且|$\overrightarrow{a}$|=1,|$2\overrightarrow{a}-\overrightarrow{b}$|=$\sqrt{10}$,则|$\overrightarrow{b}$|等于（　　）

      This is a s____ of twin brothers, Justin and Paul. Their friend Susan calls them for h____ . Justin and Paul drive to Hill Building q____ . Three man in police uniform p____  them into a green van. They are not p____ . They are the robbers. The twin brothers aren’t a____. Paul opens the back door of the van w____  a knife. They take different r____ to the police station. They meet the robbers  a ____  in the police station. They are s____ . The policemen stop the van because the back door of the van is open.

我国科学考察队去南极考察一般11月至12月抵达南极，主要原因是（    ）

亚洲气温南北差异大的主要原因是（    ）