35. What is this passage mainly about?
(A) The evolution of traffic control systems.
(B) The inventors of traffic lights in history.
(C) The functions of different traffic signals.
(D) The development of modern transportation.
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統計: A(88), B(76), C(15), D(17), E(0) #3381962
統計: A(88), B(76), C(15), D(17), E(0) #3381962