По течению реки моторная лодка проходит 40 км за 2 часа, а против течения 35 км за 2часа 30 минут. Найти скорость течения реки.

 С поля, засаженного капустой, в первый день было вывезено 58% урожая, а во второй – остальные 33,6 тонны. Сколько тонн капусты было вывезено с поля?

решите задачу:Точки А,В и С лежат на прямой а,причём АВ=5,7м, ВС=730см.Какой может быть длина отрезка АС в дециметрах?

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Нужен перевод текста, со смыслом.

I think I will begin by answering the one question that I'm sure is at the back of all your minds, "What exactly does the title of the presentation mean?" It means that many boats sailed off from English and American ports and never reached any other port. They are just "never heard of again". So I'm going to speak about mysteries at sea.

I'm going to give you an example. The ship, the President, belonged to the unlucky British and American Steam Navigation Company and she was very successful on the Atlantic. On 11 March 1841 she left New York with 136 persons on board. Two days later she disappeared and all on board went with her.

If you look at the picture you can see the even worse fate of the City of Glasgow. It was a big, beautiful boat. It left port on 1 March 1854 with 480 persons on board, and was never heard of again.

There are many theories that try to explain why the disasters took place. Among many reasons could be meetings with icebergs, and master mariners who know the Atlantic Ocean well think this is likely.

In conclusion, they are just "never heard of" as the reports say accounts for 19 Atlantic ships and their passengers and cargoes, with a heavy loss of life — about two thousand. At all times the ocean has not only been a friend but a danger too.