(A) To provide an example of tool use among animals
(B) To prove that certain species demonstrate greater ability in tool use than other species
(C)
(D)
27. The word "rudimentary" in line 21 is closest in meaning to
(A) superior
(B) original
(C) basic
(D) technical
28. It can be inferred from the statement about mother chimpanzees and their young (lines 21-23) that young chimpanzees have difficulty
(A) communicating with their mothers
(B) adding quantities
(C) making choices
(D) opening hard nuts
29. The phrase "the one" in line 26 refers to the
(A) study
(B) pair
(C) chimpanzee
(D) ability
30. Scientists concluded from the experiment with chimpanzees and chocolate chips
that chimpanzees
(A) lack abilities that other primates have
(B) prefer to work in pairs or groups
(C) exhibit behavior that indicates certain mathematical abilities
(D) have difficulty selecting when given choices