题目

设r＞0,那么直线xcosθ+ysinθ=r与圆（φ是参数）的位置关系是…(    )A.相交                            B.相切C.相离                            D.视r的大小而定 答案：思路解析：根据已知圆的圆心在原点,半径是r,则圆心(0,0)到直线的距离为d==r,恰好等于圆的半径,所以,直线和圆相切.答案：B I wouldn’t eat potatoes unless I’m really starving, in _______ case you eat almost anything. A. whose        B. one           C. what              D. which