21．A 22．B 23．D 24．A 25．A 26．C 27．D 28．B 29．D 30．C 31．D 32．B 33．C 34．C 35．B 36．F 37．G 38．E 39．B 40．A
41．C 42．B 43．A 44．D 45．A 46．B 47．D 48．A 49．C 50．D 51．B 52．A 53．C 54．B 55．D
56．dates 57．placed 58．spread 59．while 60．in 61．To distinguish 62．that 63．the 64．innovative 65．possibilities
Posted in课件