过点P(0,-2)与抛物线y2=4x只有一个公共点的直线的条数是( ) A.1条 发布时间:2017-04-30 13:09 │ 来源:www.tikuol.com 题型:选择题 问题: 过点P(0,-2)与抛物线y2=4x只有一个公共点的直线的条数是( )A.1条B.2条C.3条D.无数条
题型:选择题 —How long has the nationwide ban (禁止) on plastic bags been put into practice? -_____ the beginning of June.[ ]A. Behind B. Since C. Among D. At 查看答案