题目

根据椭圆=1(a＞b＞0)的参数方程，此椭圆上任意一点可设为 A.(acos,bsin)                                           B.(asin,bsin)C.(a2cos,b2sin)                                       D.(a2sin,b2sin) 答案：解析:∵椭圆的参数方程可写为∴椭圆上一点的坐标可设为(acos,bsin).答案:A  -----Why are you looking pleased?----Oh, I’ve just had a job _________.A．to offerB．offeringC．offeredD．being offered