17. The flowers who that / which he paints are always very beautiful.
18. The speed of light is much faster faster than the speed of sound.
19. Your package has to wrap to be wrapped carefully before it is mailed.
20. Ms Lan had an old photo album whose which she often showed to her grandchildren.
21. You'd better not drink the tap water. It could polluted could be polluted / is polluted.
22. Which is the country that whose economy is growing the fastest in the world?
23. Health and happiness are important more important than money.