3. What do you mean by...

2. Are there many differences?

1. A lot of people can't tell the difference between...

25. keep in mind 记在心上

　　 ☆交际用语☆

24. in case of 以防……

23. in honor of 纪念……，庆祝……

22. die of 死于

21. roll over 翻转

20. first of all 首先

19. first aid 急救