城市总产出与总投入之差是规模效益，最初为负值，随着规模扩大迅速变正值，在城市边际投入 发布时间：2020-09-13 10:24 │ 来源：www.tikuol.com 题型：判断题 问题： 城市总产出与总投入之差是规模效益，最初为负值，随着规模扩大迅速变正值，在城市边际投入等于边际产出时最多，然后规模效益持续下降，最终变为零甚至负值。
题型：判断题 附加题。阅读下面短文， 将方框中的句子抄写在短文的适当位置，使短文意思完整。they are so young I have to spend an hour picking them up you ask your children to do chores they learn they know how to be organized at schoolQuestion: I don't know what chores are appropriate (合适的) for my 9-year-old son and 6-year-old daughter. I know they can't do much around the house because __1__, but I want to give them some things to do in the summer because they don't have to go to school. I want to have them pick up (捡起) their toys after they play with them, because sometimes __2__. Is that a good idea? What do you have your kids do? Can you give me some advice?Advice: When __3__ you are not turning them into little servants (仆人). You are teaching them how to clean and organize (组织) things. I have two children: 10 and 11-year-old boys. They clean the floor, do the dishes and do the laundry. They break lots of plates and bleach (漂白) their clothes, but __4__! They become very responsible (负责的). They can't stand to see clothes on the floor or their beds not made. Also, __5__. 查看答案
