Определите функцию глагола to have в предложениях: Not all of us can become extremely strong or clever, but all of us can, if we have ordinary bodies and brains, improve our strength and our memory by the same means -practice. Have you ever noticed that people who cannot read or write usually have better memories that those who can? Of course, because those who cannot read or write have to remember things: they cannot write them down in a little notebook. They have to remember dates, times and prices, names, songs and stories, so their memory is the whole time being exercised

1. Тут функция проста- если бы у нас были мозги и сильное телосложение...
2.Время. Have- глагол, употребляемый в Present Perfect.
3. Have to remember- Должны вспомнить.