A-A+
A．Because the old one could not transfer signa
问题详情
A．Because the old one could not transfer signals clearly.
B．Because the old one could not send messages quickly enough.
C．Because the old one could not send more than one message at the same time.
D．Because the old one could only send two messages along the same line simultaneously.
参考答案
正确答案：C
解析：细节题。文中明确叙述了爱迪生改进旧式电报机的经过。他这么做是因为 it was impossible at that time for the system to send more than one message along the same line at the same time，这与C说法一致。
