He a letter by 6 pm yesterday.

had written

has wrote

​

В источниках, в инете пишут возраст 13-18. У тебя такого варианта нет. Я нашла статью об этом, прочитай ее

public school  particularly in England, which cater primarily for children aged between 13 and 18.
Differences between British and American English: public schoolIn the UK, a public school is a private institution for young people between the ages of 13 and 18 whose parents pay for their education. The students often live at the school during the school year. American speakers usually refer to this as a private school. In the US, public school refers to a school that is paid for from taxes and provides free education to local children between the ages of about five and 18. This is called a state school in the UK.

The lifestyle which we enjoy today is a result of countless ideas and inventions, which have taken many centuries of man’s history to develop.
1.The first great idea  was when a caveman picked up a heavy stone to help him.The use of fire was another step without which no subsequent development would have been possible.Another great move towards modern technology was the invention of the wheel by some unknown prehistoric genius.
2.Man had efficient metal weapons and was able to hunt large animals for food.  Man also discovered how to plant crops, gathering seed from wild plants, which he knew to be useful.
3. Another important invention which has contributed greatly to our modern knowledge was writing. The Greeks were the first people to use writing to record language as spoken by contemporary men; and their works are still widely read today, for information and for pleasure.
4.After the time of the Romans, the speed of discovery slowed down, and indeed many earlier discoveries were lost for hundreds of years.s important was the invention of printing, giving many men an opportunity to read and to own books which before had been available to only the wealthy few.
5.The invention of the steam engine, the condenser and piston made possible modern manufacturing processes.Farm machinery was invented, and production of larg-er food-crops became possible.The manufacture of cars began a new era in transport, and led to the appearance of lorries and buses, without which our cities would not have grown to their present size.
6.The airplane was constructed.
7.All our discoveries today are based on the ideas of men who lived before us; and without their groundwork, modern inventions would have been impossible. All nations can benefit from the knowledge left to us by earlier generations.