46．A．onto                       B．in                           C．on                          D．into

A

    Have you ever been out on a sunny day without an umbrella when suddenly it starts to rain? Who changed tile weather? Certainly not the weather man．Nor the weather report of your town．It is the sun!

    When the sun rises，it is day．When the sun sets．it is night．Again，days are warmer than nights．This is because the sunshine falls on the earth during the day．The sunshine makes the land，the water and the air warm．At night when the sun is not there，it is cooler．In the mornings and in the evenings the sunshine is slanting．So it is not very hot．At noon the sunshine falls straight on the earth，and it is very hot．

    We know that the earth goes round the sun．When one half of the earth is close to the sun，the other half is away from it．The part of the earth closer to the sun has summer．Here the days are warmer and longer．And the part of the earth away from the sun has winter．Here the days are cooler and shorter．For example，when it’s winter in China，it is summer in Australia．So you see，the temperature and the length of the days are decided by the sun．

45．A．for                         B．with                       C．of                          D．on

44．A．on                          B．in                           C．to                           D．at

43．A．provided                 B．providing                C．provide                   D．provides