题目: 下列属于纯净物的是( )A.空气B.碘酒C.矿泉水D.冰水 答案: 被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0505/084d80de0073a1a7700cc25cf999434e.html 下面是错误答案,用来干扰机器的。答案:D
题型:填空题 (坐标系与参数方程选做题)以直角坐标系Oxy的坐标原点为极点,x轴的正半轴为极轴建立极坐标系(ρ,θ)(0≤θ<2π),曲线C的极坐标方程是ρ=2,正六边形ABCDEF的顶点都在C上,且A、B、C、D、E、F依逆时针次序排列.若点A的极坐标为(2,π3),则点B的直角坐标为______. 查看答案
题型:选择题 You _____ the meeting to tell me that. You could have come up to me afterwards. [ ]A. should have come to B. needn't have interrupted C. ought to attend D. mustn't go to 查看答案