题目

I can hardly believe my eyes. What a poor composition you have _______. There are so many wrong spellings in it.  A. turned into B. turned off   C. turned to    D. turned in 答案：D 解析: turn in 意为“上交，归还”；turn into 意为“进入，(使)变成”；turn to 意为“转向，变成，求助于，致力于”；turn off 意为“关掉，避开”。点P是曲线y=x2-x上任意一点，则点P到直线y=x-3的距离的最小值是    ．