题目: —I called you yesterday evening, but there was no answer. —Oh, I'm sorry. I _______ dinner at my friend's home. [ ]A. had B. was having C. have had 答案: 答案:C
题型:选择题 — What made Mary so upset? — _____ her wallet.A. Losing B. Lost C. Because of her losing D. Because she lost 查看答案
题型:填空题 在探究“滑动摩擦力的大小与哪些因素有关”的活动中.(1)在水平桌面上,用弹簧测力计水平向左拉动木块,使其作匀速直线运动,弹簧测力计示数如图所示.根据______知识可知,木块所受的滑动摩擦力为______N.(2)小华将木块沿竖直方向截去一半后,测得木块所受的滑动摩擦力变为原来一半.他由此得出:滑动摩擦力的大小随接触面积的减小而减小.你认为他的探究过程中存在的问题是______. 查看答案
题型:选择题 【选修3-3】下列叙述中正确的是A.物体的内能与物体的温度有关,与物体的体积无关B.布朗运动是指液体分子的无规则运动C.物体体积改变,内能可能不变D.物体被压缩时,分子间存在斥力,不存在引力 查看答案