Read the passage and choose the best answer
Alexander Graham Bell was born in 1847 in Edinburgh, Scotland. His father was an expert in phonetics, the study of the sounds of languages. As a boy, Bell became interested in sounds and speech. In 1870 the Bells decided to emigrate to America. They lived in Boston, where Alexander taught in a school for the deaf – mutes. There, he began experimenting with a machine to help the deaf hear. While experimenting with this machine, Bell had an idea. Why not use electricity to send the human voice from one place to another? Bell began work on a new invention of the telephone.
What does the word “emigrate” in line 3 mean?