请告诉我语法与答案.最好有为什么A: You look very nice in your new dress today. B: Oh, really? I _________ it when it was on sale. A. buy B. bought C. have bought D. will buy

请告诉我语法与答案.最好有为什么A: You look very nice in your new dress today. B: Oh, really? I _________ it when it was on sale. A. buy B. bought C. have bought D. will buy 英语翻译这句有什么语法知识请告诉我 告诉我答案以及语法 you is a good fuck什么意思请根据语法知识告诉我 、不要纯粹的英译中! the letter is from a girl ____(name)cindy.最好有为什么 问题：I don't mind —— A.laugh at B.laughing at C.be laughed at D.being laughed at答案选D,请告诉我一下为什么选D,D是用的什么语法? A和C取什么值时,直线Ax-2y-1=0与直线6x-4y+C=01.相交；2.平行；3.垂直思路,不要只有一个答案,因为我想知道怎么做的.最好能把这类题方法告诉我 若直线AX+BX+C=0通过二、三、四象限,则系数A、B、C 英语题：This is his first trip_____the Chinese mainland after 56 years.A.back B.back to C.to D.for请告诉我您的做法,是否有什么结构与语法点,谢谢! My mother and father are ________doctor.A.all B.two C.both D.also请告诉我答案,最好有理由. 一直线的斜率k=-tanA,a∈（π/2,π）,求倾斜角最好有为什么…… n个数相加的公式最好有为什么这样做 请快点告诉我答案 请告诉我答案吧 直线y=a与函数f(x)=x^3-3x的图像有相异的三个公共点,则a的取值范围是请告诉我答案及解题过程!谢谢! 新疆与澳大利亚棉花生长共同的有利自然条件是（）：A.光热充足 B.水热组合好 C.有灌溉水源 D.土壤肥沃 答案选AC,为什么?有为什么不选BD? now you can have another Chinese stamp,now you can have another Chinese stamp,simon 希望有懂英语的朋友告诉我一下.感激不尽![请不要给我搬一大堆语法说教文来,尽量简洁,最好只有答案.] He often talks____his friends on the Internet.选择题A.to B.of C.about D.at 这道题怎么做?有没有什么语法知识,请告诉我. 请告诉我这些英语选择题选什么答案,并告诉我选择此答案的依据.