1. The question is so hard that _______students can answer it. (用a few或few填空) 2. —Is the new rule working? —Yes, ______books are stolen (被偷). (用ra few或few填空) 3. Don't worry, we still have ______minutes left. (用a few或few填空) 4. There are so ______trees on the hill. The birds can't even find a place as thei home. (用a few或few填空)