| A | B |
|---|
| replace | change |
| major | large or important |
| development | change that makes something better or more advanced |
| engineer | person who designs machines, roads, bridges, etc. |
| keep up with | move as fast as someone or somethin |
| chest | part of teh body below the neck and above the stomach that contains the rib cage |
| artificial | not created by nature |
| design | draw plans for |
| beat | make a regular movement or sound like a drum or a heart |
| attach | to connect |
| battery | a thing that aprovides electricity |
| key | essential; needed |
| demand | a need for something |
| therefore | so; thus; for that reason |
| turn into | change into a different form |
| within | inside of |
