21. The author's main point in paragraph 1 is that clay deposits
(A) conceal layers of rock
(B) can be found in various places
(C) are usually small
(D) must be removed from construction sites

17. The word "emphasize" in line 19 is closest in meaning to (A) stress (B) repeat (C) explain (D) leave out

18. Which of the following can be inferred about the findings described in paragraph 2 ? (A) Babies who are exposed to more than one language can speak earlier than babies exposed to a single language. (B) Mothers from different cultures speak to their babies in similar ways. (C) Babies ignore facial expressions in comprehending aural language. (D) The mothers observed by the researchers were consciously teaching their babies to speak.

19. What point does the author make to illustrate that babies are born with the ability to acquire language? (A) Babies begin to understand words in songs. (B) Babies exaggerate their own sounds and expressions. (C) Babies are more sensitive to sounds than are adults. (D) Babies notice even minor differences between speech sounds.

20. According to the author, why do babies listen to songs and stories, even though they cannot understand them? (A) They understand the rhythm. (B) They enjoy the sound. (C) They can remember them easily. (D) They focus on the meaning of their parents' words.

22. It can be inferred from the passage that clay is LEAST likely to be plentiful in which of the following areas? (A) In desert sand dunes (B) In forests (C) On hillsides (D) Near rivers

23. The word "accessible" in line 4 is closest in meaning to (A) buried (B) improved (C) available (D) workable

24. According to the passage, rock breaks down into clay under all of the following conditions EXCEPT when (A) it is exposed to freezing and thawing (B) roots of trees force their way into cracks (C) it is combined with alkalies (D) natural forces wear away the Earth's crust

25. Why does the author mention feldspar in line 10? (A) It is often used as a substitute for clay. (B) It is damaged by the oxides in clay. (C) Its presence indicates inferior clay. (D) It is a major component of clay.

26. The word "it" in line 13 refers to (A) iron (B) feldspar (C) granite (D) clay

27. Based on the information in the passage, it can be inferred that low-fire clays are MOST appropriate for making objects that (A) must be strong (B) can be porous (C) have a smooth texture (D) are highly decorated