课后限时自测(十四)
Ⅰ.语法填空
In ancient times，many people believed the earth was a flat disc.Well over 2，000 years ago，the ancient Greek philosophers were able to put forward two good arguments__1__(prove)that it was not.Direct observations of heavenly bodies were the basis of both these__2__(argue)．
First，the Greeks knew that during eclipses (月食)of the moon the earth was__3__the sun and the moon，and they__4__(see) that during these eclipses，the earth's shadow on the moon was always round，they realized that this could be true only__5__the earth was spherical( 球形的)．If the earth was a flat disc，then__6__shadow during eclipses would not be a prefect circle; it would be stretched out__7__a long ellipse (椭圆)．
The second argument was based on__8__the Greeks saw during their travels.They noticed that the North Star appeared lower in__9__sky when they traveled south，in the more northerly regions，the North Star appeared to be much__10__(high)in the sky.
