A、Easy to digest. B、Rich in nutrition. C、High in blood cholesterol. D、Free of harmful substances. B题目问的是鸡蛋有什么好处。由定位句可知，鸡蛋的营养价值高。

Though they are an extensive supplier of vitamin, minerals and high-quality protein, eggs also contain a high level of blood cholesterol, one of the major causes of heart disease.
    One egg yolk, in fact, contains a little more than two-thirds of the cholesterol the body needs daily. This knowledge has caused egg sales to drop in recent years, which in turn has brought about the development of several alternatives to eating regular eggs.
    One alternative is to eat substitute eggs. These egg substitutes are not really eggs. But they look somewhat like eggs when they are cooked. They have the advantage of having lower cholesterol rate, and they can be scrambled or used in baking. One disadvantage, however, is that they are not good for frying or boiling. A second alternative to regular eggs is a new type of egg, sometimes called "designer" eggs.
    Q16: What is good about the eggs?
    Q17: What happened when people came to know the high level of cholesterol in eggs?
    Q18: What has been one of the approaches to the problem of cholesterol?