they used either the rain or chalk erasers because they only had chalk.
theyusedwinpower theyusedwinpower
people invented it
I got that question too. It's very badly worded. When they are asking for 3 students in the class that made the same mistakes, they are not asking for at least 3 people that made 12 mistakes. They're asking for u to prove that there were at least 3 people that made the same mistakes as eachother.
The abacus was invented to help people calculate.
You have 25 other people. If 2 people made the same number of each mistake from 0 to 11 this would only account for 24 people, so at least one particular mistake must have been made by 3 people. 0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11. This accounts for only 24 people...
Lipman... He actually invented the pencil eraser on top of the pencil because people kept making mistakes. How hard it would without making any mistakes.
Resilient means that they deform very little and return to their original shape when the load is removed - they are what most people would tend to call hard rubbers For instance - tyre rubber
Crawling
Buttons.
bikes
benches
pickaxes
Shoelaces were invented long before people bothered to keep records of such things.
Before the refrigerator was invented, people used iceboxes, which were essentially big coolers with a block of ice. Even before that, food was preserved by salting, curing, smoking, drying, and canning.
theyusedwinpower theyusedwinpower
they read books.
Fingernails!!