阅读下面的短文，在空白处填入一个恰当的词，或填入括号中所给单词的正确形式（不多于3个单词）。   

    Mr. Green is from England. He and his wife (妻子) are teachers. They teach  (England) in Beijing. They have a boy and a girl. They are Jack and Mary. Jack is a student, but Mary is not. She is only four.

    They have two  (bike). The big bike is for Jack and  small bike is for Mary.

     Sundays, sometimes they are at home, sometimes they  (go) to the park. The Greens like China. They have a lot of Chinese friends.