In a sports team each player has a clear role，and there are few occasions members are confused or uncertain of their roles．

______________—The fresh air and the green trees.

Mr. Li is a ________ .He ______ us how toswim.

1He came to see his uncle _______ a snowy day.

The newcomer went to the library theother day and searched for ________ he could find about Mark Twain.