... in 198 1 C. in 198 3 D. in the same year when AT& T constructed a cell phone system.Câu 18: When did AT& T widely start their cellular phone system? A. in 2001 B. in 197 7 C. in 198 1 ... cell phone itself cost about $ 3, 500. In 197 7, AT & T constructed a cell phone system and tried it out in Chicago with over 2, 000 customers. In 198 1, a second cellular phone system was ... ĐỀ THI THỬ ĐẠI HỌC 20 09 Thời gian: 90 phút Circle one option A, B, C or D that best rewrites each of the following sentences:Câu...