题目

During job interviews, many graduates use the reputation and image of their schools to the full, ______ themselves to employers． A． presented                                        B． to have presented C． having presented                                D． to present 答案：D 生活处处有物理．夏天对着开水“吹气”，能使开水变凉，这是因为________，使水温下降．冬天，对着手“哈气”能使手变暖，这是因为水蒸气遇冷________，使手表面温度升高．