4 Write a word from the box in each gap. battery • built . calculator cities designed found genius . invented towers in 1973 by a man named with electronic devices. the first mobile phone to look like a phone, but it didn't only lasted for 20 minutes. However, Cooper said that wasn't The first mobile phone was (1) Martin Cooper, who was a(n) (2) He (3) look like the ones we use today. It was a very large, heavy phone, and the (4) a problem because you couldn't hold the phone up for that long. ' Since then, people have (5) out ways to make mobile phones very small. They can also be used for other things, like planning your day, or as a(n) (6) to do simple maths problems. They are used in both big (7) and small towns. They can be used in the countryside too, thanks to tall (8) that mobile phone companies have (9) - Mobile phones have become so important that most of us couldn't live without them. ​