题目

― Would you like to come to the dinner party here on Saturday?          ― Thank you. I’d love to, ______ I’ll be out of town at the weekend.   A. because                   B. and                               C. so                       D. but 答案：D如图所示，三根细绳系于O点，将物体悬挂在天花板上，当系统保持静止时，细绳受到的拉力大小分别为F1、F2和F3．下列判断正确的是（　　）A．F1＞F2＞F3B．F3＞F1＞F2C．F2＞F3＞F1D．F3＞F2＞F1