At the top of the high mountains there is very oxygen in the air.A. a littleB. littleC.

问题补充：

At the top of the high mountains, there is very oxygen in the air.

A. a little

B. little

C. a few

D. few

答案：

A. a little

(答案→)B. little

C. a few

D. few

解析：句意：在高山顶上，空气中有少量的氧。few, a few是可数的, little, a little是不可数的。

few 和little表示很少，否定的意思。a few 和a little表示一些，肯定的意思。因为氧气是不可数名词，排除C、D；根据句意故选择B。