The trains on the DLR are controlled by
A.an on-board central computer.
B.a computer engineer on board.
C.two-way radios operated by the drivers.
D.a computer center based somewhere along the line.
为了保护您的账号安全,请在“上学吧”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!