a small quantity of water.

少量的水。

huge quantities of narcotics.

大量的镇静剂。

Cheap goods are available, but not in sufficient quantities to satisfy demand.

便宜的货物倒是有，但量不足，满足不了需求。

After some initial problems, acetone was successfully produced in quantity.

最初的一些问题被解决后，大量丙酮就被成功生产出来了。

the less discerning drinker who prefers quantity to quality.

重量不重质，不怎么识货的饮酒者。

She had known Max for some years now, but he was still pretty much an unknown quantity.

她认识马克斯也好几年了，但是他仍然是个大大的未知数。