厌氧系统出现问题时，最先反映的是（）；一旦检测到系统处于欠平衡状态时，就必须加以控制

阅读理解。

     Why do plants grow in some places and not in others? Why does some land have so much growing on it,

while other land has almost no plants growing on it at all.

     To grow, plants need several things. One is warmth. In very cold places almost nothing grows. Plants also

need water. In very dry parts of the Earth only a few unusual plants can grow. That's why dry deserts

everywhere are almost not covered by trees or grass.

     Plants must also have a place in which to put down their roots and grow. They find it difficult to grow on

hard land. The town is built on hard land. The plants here can only grow in the soil between the cracks (缝隙)

of the stones.

     Another thing plants must have before they can grow is food.

     What will happen if we try to make things grow on the sandy beach? A few plants, such as beach grass,

will grow in sand, but most plants won't. Even if the weather is warm enough and we water the plants each

day, many of them will die because the sand on this beach has almost no food for plants.

1. Plants can grow ______. [ ]

A. nowhere

B. somewhere

C. anywhere

D. everywhere

2. The passage tells us that plants need            things to grow. [ ]

A. two

B. three

C. four

D. five

3. Plants like to grow in            soil. [ ]

A. dry

B. hard

C. soft

D. hot

4. From the passage, we can know most of the plants aren't able to grow on the sandy beach

    because ______. [ ]

A. the soil is too poor

B. there is too much water

C. sunshine is not enough

D. sunlight is too strong

5. Maybe the passage can be found in a _____ book. [ ]

A. travel

B. history

C. physics

D. science

与平片相比，下列哪一项不是CT的优势（）

A.密度分辨率高

B.空间分辨率高

C.解剖分辨率高

D.增强扫描有利于病变定性

E.可进行多方位重建

货车停留时间按作业性质，分为货物作业停留时间和（）时间。

以下描述氯丙嗪体内过程，哪一个是错误的

A．口服吸收不规则

B．脑内浓度可达血浆浓度的10倍

C．排泄较快

D．90%与血浆蛋白结合

E．代谢物主要经肾排出

Windows中，同时按_____三键一次，可以打开“任务管理器”，以关闭那些不需要的或没有响应的应用程序。