题目

下列何者为5x2+17x-12的因式？ (A) x+1  (B) x-1  (C) x+4  (D) x-4 。 答案：C ,3．这本杂志我已经买三天了，还没来得及看．I have had the magazine for three days，but I haven't got any time to read it．．