36. The word "They" in line 17 refers to

　　(A) mathematicians

　　(B) children

　　(C) pencils

　　(D) studies

　　37. The word "prerequisite" in line 19 is closest in meaning to

　　(A) reason

　　(B) theory

　　(C) requirement

　　(D) technique

　　38. The word "itself" in line 20 refers to

　　(A) the total

　　(B) the concept of abstract numbers

　　(C) any class of objects

　　(D) setting a table

　　39. With which of the following statements would the author be LEAST likely to agree?

　　(A) Children naturally and easily learn mathematics .

　　(B) Children learn to add before they learn to subtract.

　　(C) Most people follow the same pattern of mathematical development

　　(D) Mathematical development is subtle and gradual.

　　40. Where in the passage does the author give an example of a hypothetical experiment ?

　　(A) Lines 3-6

　　(B) Lines 7-9

　　(C) Lines 11-14

　　(D) Lines 17-20