过点A(1,2)且垂直于直线2x+y-5=0的直线方程为( ) A.x-2y+4 发布时间:2017-04-19 13:39 │ 来源:www.tikuol.com 题型:选择题 问题: 过点A(1,2)且垂直于直线2x+y-5=0的直线方程为( )A.x-2y+4=0B.2x+y-7=0C.x-2y+3=0D.x-2y+5=0
题型:选择题 Do you think it is difficult ? [ ]A. study English well B. studies English well C. studying English well D. to study English well 查看答案
题型:选择题 由NH3NO3、K2CO3、KH2PO4、MgSO4和CaCl2及一些必需的微量元素组成的培养液,用NaHCO3和H2CO3作为缓冲对调节溶液的pH值。这一培养液适于培养下列哪种生物()A.茎韧皮部细胞B.绿藻C.酵母菌D.草履虫 查看答案