回上一层第四部 第七课 --- 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
- drop a line
- Todd asked you to drop him a line when you finished the project.
- drop by
- Please drop by some other time.
- drop out
- Victoria regrets having dropped out of college, but it's too late now.
- Wagner dropped out in the middle of the race.
- dry out
- I let the towel dry out in the sun.
- The flower dried out after a few days.
