最先考虑诊断A．脑出血 B．脑栓塞 C．血管性头痛 D．SAH E．脑梗塞

实验操作和目的对应关系不正确的是

A．加热试管时，先均匀加热后集中加热——防止试管炸裂

B．点燃氢气前，一定要先检验氢气的纯度——防止发生爆炸

C．用双氧水制氧气时，加入少量二氧化锰——增加氧气生成的量

D．铁丝在氧气中燃烧时，集气瓶底部放少量水——吸收热量

Just as a book is often judged ________ by the quality and appearance of its cover, a person is judged

immediately by his appearance. [      ]

A. previously  

B. uniquely

C. outwardly  

D. initially

— _____?

— He is a computer engineer. [ ]

A. What does your father do

B. How old is your father

C. What does your father look like

D. How does your father go to work

在对字母“R”进行正反判断的试验中，反应时最长的顺时针倾斜角度为（）

A．60

B．120

C．180

D．270

饰面型防火涂料按防火性分为（）两级。

A.一、二

B.甲、乙

C.A、B

D.B、H