9. No medicine is nice; Senna is a medicine.
10. Some oysters are silent; No silent creatures are amusing.
11. All wise men walk on their feet; All unwise men walk on their hands.
12. "Mind your own business; This quarrel is no business of yours."
13. No bridges are made of sugar; Some bridges are picturesque.
14. No riddles interest me that can be solved; All these riddles are insoluble.
15. John is industrious; All industrious people are happy.
16. No frogs write books; Some people use ink in writing books.
17. No pokers are soft; All pillows are soft.
18. No antelope is ungraceful; Graceful animals delight the eye.