I.冠词填空：在下列句中空白处填入适当冠词，不需用冠词处划×。
1．There is _______ picture of _______ elephant on _______ wall．
2．This is _______ useful book．I've read it for _______ hour．
3． _______ elephant is much heavier than _______ horse．
4． _______ doctor told him to take _______ medicine three times _______ day．
5．Let's go out for _______ walk．
6．It's too hot．Open _______ door，please．
7．There is _______ woman over there． _______ woman is Meimei's mother．
8． _______ sun rises in _______ east．
9． _______ Changjiang River is _______ longest river in _______ China．
10．Are you going to do it _______ second time？
11．Washington is _______ capital of _______ USA．
