出水层段岩石坚硬、无严重出砂时才能用封隔器堵水。
参考答案：对
下列对有关主题知识的归纳错误的是
同义句变化
1. It's time for school now.
It's time ____ ____ to school now.
2. Whose yellow shirt is it?
____ ____ the yellow shirt?
3. I want anew ruler.
I ____ ___ a new ruler.
4. Please give me your new book.
Please give your new book ____ ____.
5. What time is it, please?
____ ____ ____, please?
