给水除氧的目的是什么？

检识鞣质常用的试剂是( )

A．明胶
B．AlCl₃
C．ZrOCl₂/枸橼酸
D．Ba(OH)₂
E．Mg-HCl

阅读短文，判断正(T)误(F)。

       Mike is an American boy. He is my new classmate. He is 10 years old. Mike has a brother. His name is

Nick. Nick is 163 cm. Mike is 165 cm. Mike often goes to school on foot. Nick often goes to school by bus.

They are very different. Mike likes flying kites. Nick likes listening to music.

( ) 1. Mike is an American boy.

( ) 2. Mike is 11 years old.

( ) 3. Nick is 165 cm.

( ) 4. Nick often goes to school on foot.

( ) 5. Mike likes flying kites.

在△ABC中，B=135°，C=15°，a=5，则此三角形的最大边长为______．

下面四幅图，虚线是水平运动物体的原始方向，实线是偏转方向，图中正确的是

A、A

B、B

C、C

D、D

永久性脱毛的方法常用于脱除（）。

A.细小的绒毛

B.鼻毛

C.唇毛

D.腋毛