Requirement Attributes	Indicators	Demand Category
Must-Be Attribute	14. British Pronunciation	Functional Requirements
Must-Be Attribute	15. American Pronunciation	Functional Requirements
One-Dimensional Attribute	23. Vocabulary Words for Free	Functional Requirements
	29. Past Exam Papers	Functional Requirements
	30. Simple Interface	Design Requirements
	5. Definition of Words	Functional Requirements
	7. Example Sentences	Functional Requirements
	26. Text Translation	Functional Requirements
	38. Word Book	Personalized Needs
	16. Forgetting Curve	Functional Requirements
	24. Search for New Words	Functional Requirements
	25. Listening Exercises	Functional Requirements
	39. Dictionary	Personalized Needs
	18. Phrase	Functional Requirements
	9. Root Affix Association	Functional Requirements
	19. Word Group	Functional Requirements
	17. Derivative	Functional Requirements
	21. Words Downloaded Offline	Functional Requirements
	20. Meaning Discrimination	Functional Requirements
	27. English Articles Reading	Functional Requirements
Attractive Attribute	7. Notes	Functional Requirements
Attractive Attribute	35. Import/Export Vocabulary Books	Personalized Needs
Attractive Attribute/Indifferent Attribute	22. English Listening	Functional Requirements
Indifferent Attribute	13. Write Words by Heart	Functional Requirements
	10. Picture Aided Memory	Functional Requirements
	33. Calendar Reminders	Motivational Needs
	2. Checking-in Learning	Interactive Demand
Indifferent Attribute	12. Original Movie Sound	Functional Requirements
	28. English Learning Videos	Functional Requirements
	6. Change of Word Meaning	Functional Requirements
	34. Gold/Points Rewards	Motivational Needs
	31. Word Lock Screen Wallpaper	Design Requirements
	4. Note Sharing	Interactive Demand
	11. Video Aided Memory	Functional Requirements
	32. APP Background Image	Personalized Needs
	3. Study in Teams	Interactive Demand
	1. Friends PK Learning	Interactive Demand
	37. Membership System	Design Requirements
	36. Payment for Vocabulary	Personalized Needs