以统计图表示连续性变量，可选用() A.条图 B.直方图 C.普通线图

妇女怀孕长期反复厌食、呕恶．甚至食入即吐，称为（）。

A.厌食

B.少食

C.恶阻

D.恶食

E.纳呆

影响课堂管理的因素有哪些

D

What are you going to do if you are in a burning house How will you escape Do you know how to save yourself Please read the following passage.
Escaping a fire is a serious matter. Knowing what to do during a fire can save your life. It is important to know the ways you can use and show them to everyone in the family, such as stairways and fire escapes, but not lifts.
From the lower floors of the buildings, escaping through windows is possible, learn the best way of leaving by windows with the least chance of serious injury.
The second floor window is usually not very high from the ground. An average(平均高度的) person, hanging by the finger-tips will have a drop of about six feet to the ground. It is about the height of an average man. Of course, it is safer to jump a short way than to stay in a burning building.
Windows are also useful when you are waiting for help. Be sure to keep the door closed. Or smoke and fire may be drawn into the room. Keep your head low at the window to be sure you get fresh air rather than smoke that may leaked (渗) into the room.
On a second or third floor, the best windows for escape are those that open onto a roof. From the roof a person can drop to the ground more safely. Dropping onto cement(水泥) might end in injury. Bushes(灌木丛) and grass can help to break a fall.

It is possible to escape through the windows ______.

A．if there are some bushes on the ground

B．if you are p enough

C．if you live on a lower floor

D．if you have a long rope

下列实验相关叙述正确的是（）

A.脂肪鉴定的过程是切取花生子叶薄片→染色→制片→观察

B.西瓜瓜瓤有较多的糖，因此可用于还原糖鉴定的材料

C.大豆种子蛋白质含量高，是进行蛋白质鉴定的理想植物组织材料

D.不能用植物细胞作材料观察DNA和RNA在细胞中的分布

不属于环境污染概念范畴的是（）。

A、环境质量变化

B、尚未扰乱生态平衡

C、由于各种人为原因

D、环境组成发生重大变化

E、对人类健康造成直接、间接或潜在危害