句型转换。
1.She needs a piece of paper. (改为一般疑问句)
_______ she _______ a piece of paper?
2.It's Sunday today. (对画线部分提问)
_______ _______ is it today?
3.He was talking about the old man. (对画线部分提问)
_______ _______ he talking about?
4.I went to school yesterday. (改为否定句)
I _______ _______ to school yesterday.
5.Let's show this gift to our teacher. (改为否定句)
_______ _______ show this gift to our teacher.
6.We know she is a very important person. (改为过去时)
We _______ she _______ a very important person.
7.I was runing when a car came. (改为一般疑问句)
_______ _______ running when a car came?
8.Mary often does some shopping on Sundays. (改为同义句)
Mary often _______ _______ on Sundays.
9.Tom does his homework at school. (改为一般过去时)
Tom _______ _______ homework at school.
缺失， 
缺隙稍宽，后牙则因缺牙时间久，对颌牙伸长，可摘局部义齿修复
面的外形呈斜方形