1 . With their minds so o________by research, many scientists have little time to care about their personal lives. （根据首字母单词拼写）

2 . If we examine our thoughts, we shall find them always o_________ (占据) with the past and the future. (根据中英文提示单词拼写)

3 . Parents are always seeking for toys that are able to keep their kids o________ for a couple of hours.

4 . O___________ with business matters, Helen couldn't spare time for the party. （根据首字母单词拼写）