用括号中所给单词的正确形式填空。
His pencil is in the pencil box．This is _________ （I）．
_________ （it）are nice baseballs．
I _________ （be）an English schoolgirl．
This watch is not _________ （your）．
These are _________ （Lily）photos．
Look at the picture! This is my sister and _________ （that）are my brothers．
That _________ （be not）my ruler．
I have some _________ （watch）．
This is _________ （we）room．
Is _________ （his）your father?