问题 填空题

一块正方体的石料,棱长是6dm,这块石料的体积是______.

答案

6×6×6=216(立方分米);

答:这块石料的体积是216立方分米.

故答案为:216立方分米.

解答题
单项选择题

The United States government publishes guidelines for appropriate nutrient intakes. These are known as the Recommended Dietary Allowances (RDAs) and are updated regularly based on new research in nutrition. RDAs are suggested amounts of calories, protein, and some minerals and vitamins for an adequate diet. For other dietary substances, specific goals must await further research. However, for the U.S. population as a whole, increasing starch and fiber in one’’s diet and reducing calories (primarily from fats, sugar, and alcohol) is sensible. These suggestions are especially appropriate for people who have other factors for chronic diseases due to family history of obesity, premature heart disease, diabetes, high blood pressure, and high blood cholesterol, or for those who use tobacco.Snacks can furnish about one-fourth of the calorie requirements among teenagers. Those snacks should also provide much of the day’’s allowances for protein, minerals, and vitamins. Sandwiches, fruit, and milk make good snacks for active teenagers. Food from the food pyramid may be part of any meal. A grilled cheese sandwich or a bowl of whole-grain cereal is just as nutritious in the morning as it is at noon. In addition, a good breakfast consists of any foods that supply about one-fourth of the necessary nutrients for the day.

The passage implies which of the following

A.The time of day when food is consumed affects its nutritive value.

B.Different foods can be combined to increase total nutrition value.

C.It can be detrimental to your health to eat breakfast foods later in the day.

D.When food is eaten has no bearing on its nutritive effects.