1. B. The idea of retirement is a new one.
2. CNG and LPG would meet the second objective.
3. It's not easy to solve problems posed by mass tourism.
4. CAI lacks a way letting teachers and students communication.
5. I'm qualified to purchase a gun.
《高考英语备考1号·速效编》
《高考英语备考1号·写作编》
《高中英语晨读晚记》
《高中英语错题笔记》
《零起点考大学英语》
