25．――These students have been to the Ming Tombs．

    ――Really? When         there?

A．will they go           B．did they go          C．do they go              D．have they gone

24．――Bell said, “The earth goes around the sun．”

   ――Bell said that the earth         around the sun．

A．goes                     B．went                 C．going                  D．gone

23．China has the largest population in the world, and about         of the people in the world live in China．

A．one five               B．one fifth              C．a fifth                  D．one fifths

22．They         all their money, so they have to walk home．

A．spend                 B．had spent             C．have spent             D．will spend

21．         our country’s one-child policy, now most families have only one child．

A．For                  B．Because              C．Because of            D．As

20．⑤They felt tired but happy．

19．④They cleaned the park and told the visitors the importance of protecting the environment．

18．③First they put up some notes to tell people not to destroy the nature．

17．②They went to the park to do some cleaning on foot．

16．①The Earth Day is on March 20th．