题目

如图所示，重100N的均匀木棒AB在细绳拉力作用下保持静止，请画出绳对木棒拉力的力臂和木棒所受重力的示意图。 答案：【答案】【解析】试题分析：物体受到的重力作用在重心上，方向竖直向下；拉力作用在A点，方向竖直向下，从支点B做力F的作用线的垂线，即力臂，如图。 根据所给要求，改写下列句子。每空格限填一词 1.My grandmother realized that she was old. (改为否定句)        My grandmother________ _________ that she was old. 2.We will graduate from junior school in two months. (对划线部分提问) ________ _________ will you graduate from junior school? 3.Jack is good at maths and physics as well. (保持原句意思) Jack is good at ________ only maths ________ also physics. 4.Mary is a warm-hearted girl. （改为感叹句）  _______  _______ warm-hearted girl Mary is！ 5.We will paint our new house green and white next week. （改为被动语态） Our new house ______ _______ painted green and white next week. 6. The new comer wondered what he could do in the office.(改为简单句) The new comer wondered what ________ ________ in the office.