问题 选择题

下列各组变化中均属于化学变化的是

A.纸张燃烧 石蜡融化

B.玻璃破碎 蔗糖溶解

C.苹果腐烂 酒精挥发

D.食品变质 动物呼吸

答案

答案:D

题目分析:有新物质生成的变化叫做化学变化。

A、石蜡融化只是物质的状态发生了改变,没有新物质生成,属于物理变化;

B、玻璃破碎、蔗糖溶解都没有新物质生成,只是物质的外形或状态发生改变,都属于物理变化;

C、酒精挥发只是物质的状态发生了改变,没有新物质生成,属于物理变化;

D、食品变质、动物呼吸物质的种类发生了改变,都有新物质生成,属于化学变化;

故选D。

点评:要分清是不是化学变化,就要看有没有新物质生成.有新物质生成的就是化学变化.

单项选择题
阅读理解

阅读理解

     When we think of leadership, we often think of strength and power.But what are these really, and

how do they operate?

     Leadership today is not about forcing others to do things.Even if this is possible, it is shortterm, and

tends to produce unexpected and unwanted results.If you order someone to do something against their

will, they may do it because they feel they have to, but the anger they feel will do more harm in the long

term.They will also experience fear.

     Fear causes the thinking brain to shut down, making the person unable to function at his or her best.If

they connect you with this emotion of fear, they will become less functional around you, and you will have

succeeded in not only shooting yourself in the foot, but possibly making a very good employee or partner

unable to perform effectively.Fear does no good to leadership.

     The way we influence people in a lasting way is by our own character, and our understanding and use

of emotion.We can order someone to do something, which may be part of the work day; or we can

employ them at the emotional level, so they will become fully devoted to the projects and provide some

of their own motivation.Today's work place is all about relationships.

     Anyone works harder in a positive environment in which they're recognized and valued as a human

being as well as a worker.Everyone produces just a bit more for someone they like.Leaders understand

the way things work.They know the pay check is not the single most important factor in the work life of

most people.

     The true strength of leadership is an inner strength that comes from the confidence of emotional

intelligence-knowing your own emotions, and how to handle them, and those of others.Developing your

emotional intelligence is the single best thing you can do if you want to develop your relationship with

people around you, which is the key to the leadership skills.

1. The writer thinks that it is not________for us to connect leadership with strength and power.

A. possible  

B. necessary

C. easy  

D. effective

2. People may NOT be working hard when________.

A. they're regarded as human beings

B. they like their leaders

C. money is taken as the most important

D. leaders understand the way things work

3. From the passage, we can conclude that________is the key to making a good leader.

A. developing one's emotional intelligence

B. in fluencing others in one's own way

C. producing some unexpected results

D. having confidence in one's ability

4. This passage is most helpful to those who________.

A. have strength and power

B. are going to make a speech

C. would like to be leaders

D. are to be excellent employees