[l] Scientists guess that 80% of a person's weight gain comes from genetics and 20% comes

问题补充：

[l] Scientists guess that 80% of a persons weight gain comes from genetics and 20% comes from the persons environment. By 1998, more than 130 genes and gene neighbors were found to have some link to weight gain or weight loss in people. These different genes can either work all together or work in groups. This means that different people may or lose weight with difficulty for different reasons.

[2] One example of these different kinds of combinations is a family of genes that allows people to change extra fat into heat instead of storing the fat in the body. Animals which have this same family of genes do not gain weight easily as other animals. Other genes may affect how quickly the stomach lets the brain know that it is full. If these genes slow down the passage of this information, people may eat more than they really need. Genes are also thought to be linked with a person’s fidgets in a day. Fidgeting is small movements of a persons hands, feet, arms or legs usually when the person is nervous or excited. Fidgeting actually uses a lot of energy over a day and his energy usually comes from burning fat.

[3] In one experiment about weight gain, researchers wanted to see how much energy different people used when they were resting. People in the experiment were asked to lie on a bed and not move for 40 minutes. Researchers then measured the energy the person used for breathing. They found that different people in the study used very different amounts of energy for this one job, breathing. Researchers calculated that some people in the study burned 1,067 calories per day while others burned up to 3,015 calories. Those people who burn fewer calories doing normal work or exercise have a slow metabolism(新陈代谢).

【小题1】What is the main idea of this passage? ( no more than 10 words. )

【小题2】When may people eat much more than they really need ? ( no more than 12 words )

【小题3】Please fill in the blank in the first paragraph with proper words or phrases to complete the sentence. (no more than 5 words. )

【小题4】What’s the conclusion of the experiment? ( no more than 15 words. )

【小题5】What does the underlined word it (in Paragraph 2) probably refer to? (no more than 3 words)

The relation between gene and weight gain.

答案：

(答案→)The relation between gene and weight gain.

解析：文章主要讲解了科学家发现基因与增肥之间的关系。

【小题1】整篇文章从第一段中可以看出，文章主要讲解了科学家发现基因与增肥之间的关系。即The relation between gene and weight gain.

【小题2】从第二自然段If these genes slow down the passage of this information, people may eat more than they really need. 可知，当基因没有及时传递信息给大脑时，即When the genes don’t pass the information to the brain on time./ When the genes slow down the information to the brain.

【小题3】后文讲到了对于增肥与基因之间的关系，科学家做了实验，所以可知，这里填gain weight easily/put on weight easily/ become fat easily句意：这意味着不同的人增肥或减肥很困难是因为不同的原因。

【小题4】从最后一段知，不同个人每天消耗卡路里是不同的，即In general, different people burn up different amount of calories every day.

【小题5】从第二段知，别的基因会对胃是否饱了这样的信息传递速度产生影响，故it指代the stomach