- How long does it take to get to the airport?
- Forty minutes. But it's foggy today. I'm not sure _________ the highway will be closed soon. Let's set off earlier.
— I was listening carefully but I could not ________ everything he said. He spoke too many local idioms.
(1)解方程:3+x4-x=12;
(2)解不等式组:3x-1≥x+12(2x-1)<5x+1