tailieunhanh - The official guide to the toefl ibt third edition part 60

This eBook gives you instruction, practice, and advice on strategies for perform¬ing well on the TOEFL iBT. Chapter 1 provides an overview of the test, information about test scores, and an introduction to the on-screen appearance of the different parts of the TOEFL iBT, along with general test-taking suggestions. | TOEFL iBT Practice Test 2 month is how long the Moon takes to move around the Earth. And a year is the time it takes for Earth to move around the Sun right So they re all based on natural events But the natural clocks of Earth the Moon and the Sun run on different times and you can t divide any one of these time periods by another one without having some messy fraction left over. I mean one lunar month that s the time it takes for the Moon to go around Earth one month is about 29 and a half days . . . not really a nice round number. And one year is a little more than 365 days. So these are obviously numbers that don t divide into each other very neatly. And this makes it pretty difficult to create some sort of tidy calendar that really works. Not that different cultures haven t tried. Have any of you ever been to Stonehenge pause No . . . you know that amazing circle of giant stones in England Well if you ever go and find yourself wondering why this culture way back in prehistoric England would go to so much work to construct this monumental ring of enormous stones . . . well keep in mind that a lot of us think it was designed at least partially as a calendar to mark when the seasons of the year begin according to the exact day when the Sun comes up from a particular direction. I have colleagues who insist it s a temple maybe or a tomb . . . but they can t deny that it was also used as a calendar . . . probably to help figure out for example when farmers should begin their planting each year. The Mayans in Central America also invented a calendar but for a different purpose. The Mayans especially the royalty and priests wanted to look at long cycles of history so the calendar they used had to be able to count far into the future as well as far into the past. And not only were the Mayans keeping track of the natural timekeepers we mentioned before Earth the Moon and the Sun but another natural timekeeper the planet Venus. Venus rises in the sky as the morning star .