回上一层第11部 第九课 --- 请重复跟读，直到可以於声音档的留空之间唸完整句為止；熟练之后您必将可以 "脱口而出" 地说出标準的美式英语
- tie up
- All the employees were tied up with work and unable to show me around.
- Most of their money was tied up in real estate.
- till now
- I've been working all night till now.
- tire out
- Agatha was tired out after the hike.
- tired of
- I am tired of explaining what my job is about.
