题目内容：

Around the world, eggs have been a breakfast staple（重要部分）for all good reasons. After all, an egg is a storehouse of vital nutrients, making it an essential part of a healthy diet. And for those of you who are afraid of having this power food because you're worried that it will add to your weight, remember, one egg contains about 80 calories and about five grams of fat. Hence, smart consumption is a far healthier option.

Eggs are a well-known rich source of protein — an important building block of bones, muscles, skin, and blood. The body uses protein to build and repair tissues as well as making other body chemicals. Unfortunately, unlike fat and carbohydrates(碳水化合物), the body does not store protein, and therefore has no reservoir to draw on when it needs a new supply. Thus eggs are the perfect sources and a smart food choice for those who reduce their intake of carbohydrates in a bit to lose extra weight.

Another important nutrient you'll find abundantly in egg white is riboflavin or Vitamin B2. And for all of you wondering what's the benefit of this nutrient, Riboflavin is a water-soluble(水溶性) vitamin which is involved in vital processes in the body and is necessary for normal cell function, growth, and energy production.

The yolk, which many of us avoid out of fear, is actually a very healthy food, if consumed in moderation(适度). Mainly fat, the yolk contains 1.33 gm of cholesterol（胆固醇） per 100 gms and is a rich source of vitamin A, B vitamins, calcium, phosphorous(磷) and iron. Incidentally, the iron found in the yolk is easily digested in the body. According to nutrition experts, one can eat one whole egg every day without harming one's cholesterol and other blood-fat levels. But for those who crave for more eggs, you can reduce fat by having one whole egg and the whites of the rest of the eggs.

1.Eggs are regarded as important in breakfast because__________.

A. it is a custom to have eggs in the breakfast.

B. they are sold at a low price.

C. they are high in calories and low in fat.

D. they can provide people with many nutrients.

2.When our body is short of protein, we may____________.

A. feel tired and sleepy.

B. feel discomfort in our legs.

C. get tired of eating eggs.

D. be eager for other chemicals.

3.Which of the following is true about protein?         .

A. It can’t be stored in the body.

B. Fat can be changed into protein.

C. It is a kind of carbohydrate.

D. Our body can only get protein from eggs.

4.We can infer from the last paragraph that____________.

A. the author suggests we only eat the whites of eggs.

B. eating enough yolk can reduce cholesterol in the body.

C. iron and phosphorous in the yolk are difficult to digest.

D. high blood-fat level can do harm to our health