Калейдоскоп будней

Познавательный урок английского языка в 5 классе
Поступление в частную школу Ступени в Москве

In our English lessons we learnt about our teeth.

People cleaned their teeth with wood and animal hair before William Addis invented the first toothbrush in 1780.

We spoke about our milk teeth, our permanent teeth and going to the dentist. We learnt the names of our different teeth and how to look after them properly.

Then we did a dentist's experiment:
We needed a toothbrush, some toothpaste with fluoride, 2 eggs, a bottle of vinegar and 2 clear plastic cups.

First, we brushed one of the eggs with toothpaste.  

Next, we put the eggs into cups which had vinegar in them. Then, we watched to see what happened. 

We watched the eggs start to bubble when the vinegar attacked the minerals in the egg shell.