影响注水量下降的原因是什么?
参考答案:
有五点:
①地面设备管线影响;
②井下水嘴、滤网被堵;
③地层孔道堵塞;
④注水压差变小;
⑤注水井井况变差。
在下列各句的空白处填入一个适当的词,使句子意思完整,语法正确。
1. I want to be a _______. I like helping doctors and looking after patients.
2. Dad, I'm hungry. Can you _______ supper for me?
3. It's very _______ today. Put on warm clothes when you go out.
4. We should take more exercise. It is good _______ our health.
5. You will have a good time _______ you go to the party.
两个不同的两位数,积最大是( ),最小是( )。