56．Some scientists believe that most of the time birds’ singing is actually . (A)．an expression of happiness (B)．a way of warning (C)．an expression of anger (D)．a way of greeting

60 ．The policemen were told “to look the other way” (the underlined part in Paragraph 2) so that . (A)．they could watch the car coming from the other direction (B)．the car could go faster than four miles an hour (C)．they could make sure no one was in the way (D)．the car would not hit them on the road