构成细胞膜的基本骨架是[ ] A．蛋白质分子 B．一层磷脂分子 C．两层磷脂分子

监狱行刑法律关系不同于行政法律关系，它的______。

A．主体特定

B．权利特定

C．义务特定

D．客体特定

When it started to snow, we turned round and ________the hotel.

A．got by

B．searched for

C．made for

D．cleared up

在实验室配制石灰水时，小明同学将两药匙熟石灰样品放入小烧杯中，向其中加入一定量的蒸馏水，充分搅拌后发现烧杯底部仍有不溶性的固体，于是他认为熟石灰样品已经变质．小艳同学不同意他的判断，你认为小艳同学的理由是______．针对该熟石灰样品的成分同学们展开了讨论，请你参与讨论并完成实验报告．

【提出问题】熟石灰样品的主要成分是什么？

【作出猜想】甲同学猜想是Ca（OH）₂；乙同学猜想是CaCO₃；你认为是______．

【实验与结论】请你通过实验验证你的猜想：

阅读理解。

     Things always seem different from in normal (平常的) times to people when he or she is not feeling well.

Perhaps, many of us know this rule, but we do not care about it. At such times, things make life hard for

people in little ways. For example, when I am not in good condition, I can never find the things I need. To my

surprise, it seems that the things I need have moved from all the places where I expect to find them. If I need

something, I can never find it quickly.

     Sometimes when we are not well, we will find that boxes become heavier when lifting them, that doors

don't want to open much more easily when trying opening them, that wind becomes even colder when facing

it, that the sun becomes much hotter when under it, that cars don't run better when driving it and the distances

are longer than they were when we felt fine.

     Why does it happen? The things around us usually do what they should do as long as we are well and strong.

But when we aren't in good condition, things often tell us that they are really not our friends but our enemies.

It is wrong. In fact, everything keeps the same. Only because we are disturbed (打扰) by the bad mood (情绪),

we get the wrong feeling that everything is in the opposite direction against us. If we keep calm in the bad times,

things will be the same as usual.

1. According to this passage, why does the writer feel everything is unusual in bad condition?

A. Because everything changed.

B. Because the writer has changed everything.

C. Because the bad conditions influence (影响) his finding the right things.

D. Because the writer feels very sad and does not want to find the right things.

2. What does the underlined sentence mean?

A. When we feel bad, things do not look like our enemies.

B. When we feel good, we can know something about our enemies.

C. When we feel bad, things can help us as our friends.

D. When we feel good, we feel that things are our friends.

3. What does the writer want to tell us in this passage?

A. When we are in bad condition,we can feel that everything is usual.

B. When we find that boxes become heavier than usual, we must be in a bad emotion.

C. If we meet trouble, we should keep calm.

D. If we meet trouble, we should find ways to get ourselves out of it.

公路工程施工现场生产要素管理包括劳动力组合、主要材料要求、主要机械设备的配置与组合等内容。是项目管理的重要内容，对资源合理配置和有效使用、保证项目实施的顺利进行、降低工程成本起着重要的作用。
根据场景，回答下列问题。

选择施工机械的原则有( )。

A．施工机械与工程的具体实际相适应

B．使用机械应有较好的经济性

C．应能保证工程质量要求和施工安全

D．应能保证工程进度要求

E．有合理的机械组合