题目

有15袋饼干，其中14袋同样重，另一袋质量轻一些，用天平称，至少称次能保证找出这袋较轻的饼干。 答案：【1】3 — Peter has good grades in all his subjects, but he never shows off.              — I agree. He is very 　　　.          A. powerful             B. creative         C. modest              D. generous