Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
It was（ ）of him to have broken a vase while he was shopping in the supermarket. (care)
【正确答案】：CARELESS
【题目解析】：
本题考查的是常见名词的衍生形容词。
由was和of可知，空缺处应填形容词构成“be +adj+of +sb.”结构表示某人的某种内在特征，分析语境，打破花瓶对应于粗心，care加上否定后缀-less衍生为careless意为“粗心的”。
句意：他实在是太粗心了，在超市购物时打破了一个花瓶。