Rewrite the sentences.按要求改写下列句子。
1. This is a short ruler. (改为一般疑问句)
____________ a short ruler?
2. The window is smooth. (对划线部分提问)
How ______ the window ______?
3. Is it a toy elephant? (肯定回答)
______, it ______.
4. How does the apple feel? (根据实际情况回答)
It ____________.
5. The book is thin. (改为否定句,但意思不变)
The book is ____________.