Before there were machines, every product had to be done manually. Even handling of dangerous substances were done by humans without proper protection. This resulted in a lot of health problems but people didn't care because they were given jobs. So when the machines were introduced, millions of lives changed. This book will tell you what
Read More
Before there were machines, every product had to be done manually. Even handling of dangerous substances were done by humans without proper protection. This resulted in a lot of health problems but people didn't care because they were given jobs. So when the machines were introduced, millions of lives changed. This book will tell you what
Read Less
