upon the look

例句：

1. 1. He was upon the roof of the building when it collapsed.
   他站在建筑物的屋顶上时，它倒塌了。
2. 2. She sat upon a bench in the park.
   她坐在公园里的长椅上。
3. 3. The meeting will be held upon the 20th of this month.
   会议将在本月20日举行。