题目

如图所示，是某弹簧的弹力F和它的长度x的关系图象，则该弹簧的劲度系数等于（    ） A．       B．       C．    D． 答案：C—The doctor told me not to eat too much，but I find it difficult．—The doctor is right．________you eat，________you will be．A．The less；the healthierB．The less；the more healthierC．The more；the healthierD．The more；the more healthier