He kept a notebook about his ___ with the telephone.

Someone who helps a scientist with his work is a/an ___.

A telephone is a ____ that conveys sound over a distance.

Convey means ___.

The electrical ____ needed to build a telephone were known in 1831.

In 1854 Bourseul suggested ___ speech electrically.

Bell's accomplishment came as a ____ result of his attempts to improve the telegraph.

Make better: ____

The Morse code telegraph was _____ to receiving and sending one message at a time.

There are _____ images of Doctor Strange here!

Here you can see some font _____ of the letter A.