您要查找的是不是：
- 学下棋难吗? Is it difficult to play checkers?
- 吗 morphine
- 难 problem
- 很难吗? Is it difficult?
- 工学 engineering
- 入境难吗? Is it hard to get into it?
- 流行病学 epidemiology
- 免疫学 immunology
- 难的 hardy
- 是吗 is that right
- 金融学 Finance and Banking
- 难过的 sorry
- 工学学士 B.E. [bachelor of engineering]
- 你好吗？ How are you?
- 在学 residence
- 难看的 malformed
- 你知道吗 did you know
- 商学 comercial science
- 不难 It's no big deal.
- 是吗？ Is it really?
