Across
- 2. 共同
- 4. 100 years
- 7. to make something simpler
- 12. why do the lights works? Computers, cell phones?
- 14. a sequence with a constant ratio （不变的比例）between terms
- 15. from big to small
- 16. a member (分子）of a sequence
Down
- 1. a cold season
- 3. the verb for multiplication
- 5. to make something bigger
- 6. what you get when you subtract two numbers
- 8. 连续
- 9. an ordered (有次序) pattern (模式) of numbers
- 10. a sequence where the difference between numbers is constant （不变）
- 11. to make something smaller
- 13. the study of nature