题目

A. energizing   B. contrary       C. valuable       D. upset       E. alternatively F. schedule     G. recommended   H. available      I. development  J. structured K. assist     Teachers always plan down to the minute what their students will be doing. This is good for kids, because it teaches them to stay on task and follow a ___41____. But most homes aren’t run this way. If parents do plan their children’s lives minute by minute, what happens when that child grows up and goes to college? At some point, kids need to learn to manage their own time. 已知向量a、b满足a+b=（0，1），a-b=（-1，2），则a•b= ．