形容词 hard:

1. not easy; requiring great physical or mental effort to accomplish or comprehend or endure

2. dispassionate;

3. resisting weight or pressure

4. very strong or vigorous

5. characterized by effort to the point of exhaustion; especially physical effort

6. produced without vibration of the vocal cords

7. (of light) transmitted directly from a pointed light source

8. (of speech sounds); produced with the back of the tongue raised toward or touching the velum

9. given to excessive indulgence of bodily appetites especially for intoxicating liquors

10. being distilled rather than fermented; having a high alcoholic content

11. unfortunate or hard to bear

12. dried out

Hardi哈尔迪hardadj.硬的；困难的；棘手的；坚强的；残酷的；用力的；液态的；严寒的；确凿的adv.努力地；强烈地；严重地；坚定地hard berth硬卧票hard pointn.硬点hard usage粗略利用hard sells软卖hard light强光hard chalk硬白垩hard links[计] 硬链接hard cider发酵的苹果汁,烈性苹果酒hard brick硬砖hard smash大力扣杀

1. The thirtieth math question was the hardest.
   第三十道数学题是最难的。
2. The hardest thing is writing a recommendation for someone we know.
   最难的事情，是为一个认识的人写介绍信。