题目

We all know what it’s like to get that phone call in the middle of the night. That night’s call was no different. “Hello?” My heart beat hard. “Mama?” The voice answered. My thoughts immediately went to my daughter. “Mama, I’ve been drinking. I nearly ran off the road a few miles back. All I could think of was if it would hurt you if a policeman came to your door and said I’d been killed. I want to come home. I know running away was wrong. I know you’ve been worried. I should have called you days ago but I was afraid.” My senses were clear now, “I think……” 过双曲线＝1上任意一点M作它的一条渐近线的垂线，垂足为N，O为原点，则△MON的面积是________．