题目内容：

It’s 3 o’clock and you’ve been hard at work. As you sit at your desk, a strong desire for chocolate overcomes you. You try to busy yourself to make it go away. But it doesn’t. Here is another situation. Perhaps you are not feeling well. The only thing you want to eat is a big bowl of chicken soup, like your mom used to make when you were sick as a child. Food cravings are a strong desire for a specific type of food. And they are normal.

Scientists at the website How Stuff Works compare hunger and cravings this way. Hunger is a fairly simple connection between the stomach and the brain. They even call it simply “stomach hunger.” When our stomachs burn up all of the food we have eaten, a hormone (荷尔蒙) sends a message to one part of the brain for more food, which regulates our most basic body functions such as thirst, hunger and sleep. The brain then produces a chemical to start the appetite and you eat. Hunger is a function of survival.

A craving is more complex. It activates (使活跃) brain areas related to emotion, memory and reward. These are the same areas of the brain activated during drug-craving studies. So, some scientists call food cravings “mind hunger.” People often crave foods that are high in fat and sugar. Foods that are high in fat or high in sugar produce chemicals in the brain. These chemicals give us feelings of pleasure.

In a 2007 study, researchers at Cambridge University found that “dieting or restricted eating generally increases the possibility of food craving.” So, the more you deny yourself a food that you want, the more you may crave it. However, fasting is a bit different. They found that eating no food at all for a short period of time lessened food cravings.

So, the next time you crave something very specific, know that your brain may be more to blame than your stomach.

1.What is the function of the first paragraph?

A. To remind readers of their own special food.

B. To deepen the understanding of hunger.

C. To report the discovery of craving study.

D. To lead to the topic of the whole passage.

2.What do we learn about food craving?

A. It shows food is linked to feelings.

B. It ensures a person survives hunger.

C. It means the stomach functions well.

D. It proves the brain decides your appetite.

3.What’s the likely result of dieting?

A. The decrease of chemicals.    B. The increase of food desire.

C. The refusal of fat and sugar.    D. The disappearance of appetite.

4.What does the passage mainly discuss?

A. The functions of brain areas.    B. What hunger is all about.

C. The findings of food craving.    D. What dieting may bring us.