根据所给的汉语提示完成单词。

1．Mr. Ma always           （担忧）about his son, because he doesn't study hard．

2．Is           （地理学）your favorite subject?

3．Many people in other countries are interested in Chinese           （文化）．

4．There are about two           （百）students in the music club．

5．In winter, it is cold           （外面）, so we always want to stay in the warm house．