隋朝大运河以洛阳为中心，北达____（写古称）；南至____（写古称），全长两千多公里。
—Sunny.
A
Linda，14
My mother does most of the housework like cooking and folding the clothes.My father can only do the washing，sweep the floor and take out the rubbish.He really needs to learn how to do the housework.
Celina，13
My mother and my father do 50% of the housework each.My mother does the washing and cleans the living room.My father makes the bed and drives me to school.
Paul，16
My father doesn't do a lot but he tries to help.He hangs__up the clothes after my mother washes them and my mother is happy that he always gives her a hand.
Bill，15
My mother is a doctor.She is busy with her work every day，so she has little time to do the housework.In fact，she isn't good at doing it.So my father has to do most of it.Sometimes my grandmother comes to help.
《世界文明史》介绍：罗马成文法的组成部分之一“是罗马城市行政官在执法过程中所做的决定……行政官……可以根据每一个别案例的情况做出裁量，而不必僵硬地按照有关法律条文的字面含义进行判决。他的这种决定成为事实上的判例法。”由此可见，罗马法的显著特点是
在四边形ABCD中，若AB→+AD→=AC→，且AB→+AD→·CB→-CD→=0，则（ ）
