题目

---- Have you heard something about MH370 ?    ----- Yes. It was missing         March 8, 2014.       A. on        B. at         C. in       D. for 答案：A若θ∈R，则复数z=2（cosθ+sinθ）+（sinθ-cosθ）i在复平面内对应的点组成的图形是 ．