13.　 He ______ ______ the river yesterday. (掉进)

12.　 ______ _______ (根据) this legend, people _______(煮) water to drink over an open fire.

11.　 This beverage was _______ (发现) over 3 _____(千) years ago.

10.　 The tea was invented ______ ______. (偶然地)

9. The chef ________ lots of salt on the potato chips. (撒)

8. The customer said they weren’t _____ enough. (咸)

7. The customer was happy __________ _______ ______. (最终)

6. The customer thought that the potatoes weren’t ______ enough. (薄)

5. The potato chips were invented _________ ______. (错误地)

3. It ______ _______ _______ scooping really cold ice cream. (被用来……) 4. What do you think is the most _______ invention? (令人烦恼的)