A．Because the old one could not transfer signals clearly.
B．Because the old one could only send two messages along the same line simultaneously.
C．Because the old one could not send messages quickly enough.
D．Because the old one could not send more than one message at the same tim

A．He is afraid that his chance of getting the job is slim.
B．He wonders whether he can have enough time to do the job.
C．He fears that the job will be too hard for him to do.
D．He fears that the job will be too borin