Question

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

A．a little

B．little

C．a few

D．few

Answer 1

B

试题分析：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。