分类：教育/科学-学习帮助
问题：两道单选题,都有一点模棱两可,邀请大家讨论~1Attimes,h 
1 At times,he need extra oxygen to _____ his breathing. ntinue st rce pport2 There must have been 25____30 pills left in the bottle,he can't have taken them all! d C.butD.or为避免影响思考我不给出所谓的"标准答案",反正我是很迷惑啦~诚请大家写出自己心中的最佳答案和理由~谢谢!~
回答：1 At times,he needed extra oxygen to _____ his breathing.
 ntinue
 st
 rce
 pport
选B,他需要氧气来维持呼吸,A做持续之意是不及物动词

2 There must have been 25____30 pills left in the bottle,he can't have taken them all!
 d
 
C.but
D.or

选D,这里需要的是连词,不是介词
瓶子里有25或是30颗药留下,他不可能全吃了