Telegraph and telephone (1)(to be) both wire-based electrical systems, and Alexander Graham Bell’s
success with the telephone (2)___(to come) as a direct result of his attempts to improve the telegraph.
When Bell (3)___(to begin) experimenting with electrical signals, the telegraph (4)___(to be) an
established means of communication for some 30 years. Although a highly successful system, the
telegraph, with its dot-and-dash Morse code, basically (5)___(to limit) to receiving and sending one
message at a time.

1) to was

2) to came

3) to began

4) to were

5) to limited

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Telegraph and telephone are both wire-based electrical systems, and Alexander Graham Bell’s success with the telephone came as a direct result of his attempts to improve the telegraph. When Bell began experimenting with electrical signals, the telegraph was an established means of communication for some 30 years. Although a highly successful system, the telegraph, with its dot-and-dash Morse code, basically limited to receiving and sending one message at a time.