【题目】有天晚上天气很暖和，我熬到11点半故意不睡觉，为的是好好看看月亮。
One evening, when it was so warm, I stayed awake until half past eleven in order to have a good look at the moon by myself.

【答案】on；purpose
【解析】on purpose固定短语，”故意地“，所以填(1). on (2). purpose 。