Our eating habits have changed, ______ has our way of life.

We each have a unique genetic (基因的，遗传的) make-up. Every cell of your body has the same set of about 100,000 separate genes made of DNA. These are the instructions for producing a person. Genes decide everything from the colour of your skin to the way your brain works. You have one of several billion combinations of DNA which come from the random mixing of your parents’ genes. Except for identical twins (同卵双胞胎), no one has the same combination as another person. You are unique! You are unique in another way too: in the way you are raised and all the experiences you have from before birth to adult life. These experiences influence you, your behaviour and attitudes, and the choices you make.
But are genes or life experiences more important in shaping your appearance and personality? Scientists are studying twins to find out. One set of twins occurs every 70 births---some are identical and others are non-identical twins. Identical twins are special because they share exactly the same genes and often the same environment. Non-identical twins are more like ordinary brothers and sisters.
Some identical twins have been adopted and brought up in different homes. With identical genes but a different home environment, scientists can study twins to see how much a particular feature depends on the genes we inherit. For example, we know that eye problems, like short-sightedness, are mostly genetic. But resistance to pain is largely dependent on experiences. Genes also influence our eating habits. Identical twins brought up apart often like to eat at the same time of day and feel full after eating the same amount. Non-identical twins in similar circumstances have more varied eating habits. Identical twins are also more likely to follow the same patterns for marriage and divorce than non-identical twins.
Scientists are trying to identify the different genes that influence our behaviour. Some people are thrill-seekers and get into risk-taking and adventurous activities. They take up extreme sports like bungee jumping and possibly take drugs. Scientists have discovered a gene which affects this.
We could ask, “Are our lives determined by our genes or our upbringing?” Scientists are learning more all the time, but it is certainly true that both are important in making us who we are.
【小题1】What is the main idea of the first paragraph?

第三部分：阅读理解（共20小题；每小题2分，满分40分）
阅读下列短文，从每题所给的四个选项（A、B、C 和D）中，选出最佳选项。
Our eating habits(习惯) are very important for good health and a strong body. There are times when most of us would rather eat sweets and ice-cream than meat and rice. Sweets and ice-cream are not bad if we eat them at the end of a meal. If we eat them before a meal, they may take away our appetite(食欲). It is important for us to eat our meals at the same time each day. When we feel hungry, it is a sign that our body needs food. When we feel angry or excited, we may not want to eat. A long time ago, in England, some judges(法官) used to decide whether a man was telling the truth by giving him some dry bread. If the man could not eat the bread, it showed that he was telling lies. Although this seems very strange and rather foolish, it is indeed a very good way of finding out the fact. A man who is worrying about something has difficulty in eating anything dry. Because he is worrying, he loses his appetite and does not want to eat.
56. We must have good eating habits because ____.
A. we want to eat more                B. we want to enjoy our meals
C. we want to be healthy and strong      D．we want to have a good appetite.
57. It is good to eat sweets and ice-cream ____.
A. when we are hungry . B. when we want to  C. after the meal D. before the meal
58. We'd better have our meals ____.
A. at the same time each day         B. when our work is over
C. when the meal is still hot          D. when every one of the family is home
59. According to the judges in England, if a man tells a lie, he____.
A. eats dry bread easily          B. eats dry bread with difficulty
C. eats a lot of dry bread         D. drinks milk with difficulty

B

Our eating habits(习惯) are very important for good health and a strong body. There are times when most of us would rather eat sweets and ice-cream than meat and rice. Sweets and ice-cream are not bad if we eat them at the end of a meal. If we eat them before a meal, they may take away our appetite(食欲). It is important for us to eat our meals at the same time each day. When we feel hungry, it is a sign that our body needs food. When we feel angry or excited, we may not want to eat. A long time ago, in England, some judges(法官) used to decide whether a man was telling the truth by giving him some dry bread. If the man could not eat the bread, it showed that he was telling lies. Although this seems very strange and rather foolish, it is indeed a very good way of finding out the fact. A man who is worrying about something has difficulty in eating anything dry. Because he is worrying, he loses his appetite and does not want to eat.

61. We must have good eating habits because ____.

A. we want to eat more                B. we want to enjoy our meals

C. we want to be healthy and strong      D．we want to have a good appetite.

62. It is good to eat sweets and ice-cream ____.

A. when we are hungry . B. when we want to  C. after the meal D. before the meal

63. We'd better have our meals ____.

A. at the same time each day         B. when our work is over

C. when the meal is still hot          D. when every one of the family is home

64. According to the judges in England, if a man tells a lie, he____.

A. eats dry bread easily          B. eats dry bread with difficulty

C. eats a lot of dry bread         D. drinks milk with difficulty

65. A man who is angry ____.

A. has a better appetite          B. likes to tell lies

C. likes to eat ice-cream         D. has a poor appetite

Choose what to eat is no longer as easy as it once was. Our eating habits  1.        

have changed , as have our way of life. And the fuel we need for our       2.        

body is also different. Tradition diets often have too much fat and too      3.         

much calories for the 21^st-century person. If we want to keep up with the   4.        

high pace of modern life, we had better to learn to make the right choices   5.       

about what and how we eat. Because we have so much to choose, many    6.       

companies offer advice about what we should eat. It’s good if we spend our  7.      

time and money in buying food and keep a balanced diet. Instead of eating   8.     

expensive diet or going on unhealthy diets, we can simply try to eat little    9.    

sugar and take more exercise. I hope that everyone keeps a good health.    10.