论述疱疹性口炎的鉴别诊断。

小明为了探究空气冷却时有什么现象发生，准备把冰棒放在茶杯中进行观察。于是，从冰箱的冷冻室中拿出一根冰棒。小明发现硬邦邦的冰棒上附着“白花花”的“粉”；剥去包装纸，看到冰棒在向下冒“白气”，他把这根冰棒放进茶杯里，不一会儿，茶杯外壁逐渐形成了一些小水珠，像是茶杯在“冒汗”。你能就上述三个现象的成因做出解释吗？

（1）“白花花的粉”的成因是                                        ；

（2）“白气”的成因是                                                    ；                                  

（3）“冒汗”的成因是                                                   。

冠心病二级预防方案中，符号的意义A：________、________；B：________、________。

以下有关琥珀胆碱的叙述，错误的是：

A．用药后常见短暂的肌束颤动
B．有神经节阻断作用
C．连续用药可产生快速耐受性
D．肌松作用出现快，持续时间短
E．可被血浆假性胆碱酯酶水解破坏

Molly信箱是一个报刊栏目，主持人Molly回答读者提出的各种问题。第1至5题是五位读者的来信。

请从A、B、C、D、E和F中为每封来信选出最合适的回复。选项中一项是多余选项。

( )1. Dear Molly,

     I have a problem. My parents are always talking to me about studying. They want me to study harder

so I can go to a good school. I know studying is very important, but my parents put too much pressure

on me. How can I explain to my parents that I need some free time?

                                                                                                                         ------ Overworked

( )2. Dear Molly,

     My best friend Tony is a nice young man, but he has a bad habit. He is always late. No matter where

he is going to what he is doing, he is never on time. Once he turned up thirty minutes late for a meeting!

What can I do to break him of this bad habit? 

                                                                                                                         ------ Worried

( )3. Dear Molly,

     I have a new roommate named Louis. He is a good friend of mine, but he is driving me crazy because

he is very untidy. He leaves his dirty clothes everywhere, and he never makes his bed. I am extremely neat.

What can I do?

                                                                                                                        ----Unhappy

( )4. Dear Molly,

     My cousin plays computer games a lot and he keeps on talking to me about various games. I don't have

any interest at all, but I find it difficult to stop him without hurting his feelings. Would you kindly give me

some advice?

                                                                                                                        --- Shy

( )5. Dear Molly,

     I'm feeling upset these days because the result of my last English exam was not as good as I had expected. My teacher comforted me, saying "Don't worry. You can do better next time." But I'm still feeling bad. I need

your help. 

                                                                                                                        ----Disappointed

A.

B.

C.

D

E.

F.

排水系统布置应遵循的原则有（）。

A、给水系统一般由给水泵、给水管道和阀门组成

B、按水源种类可将给水系统分为地表水和地下水给水系统

C、镀锌钢管、不锈钢管、PPR管等是目前建筑给水的主要管材

D、PVC材质的给水管目前在我国广泛使用