单项选择题

Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions.
Now, listen to the passage.
Before the Bell Company became a publicly held corporation, how were the calls passed to their destination

A．Through manual switchboards.
B．Through reading manuals.
C．Through electronic switchboards.
D．Through voice switches.

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单项选择题

单项选择题

单项选择题

Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now, listen to the passage.Before the Bell Company became a publicly held corporation, how were the calls passed to their destination