litre

这辆车每升油能跑很远。

This car can go far on one ___litre of petrol.

增税将使每升汽油增加4便士。

The tax increase will add 4p to a ___litre of petrol.

这瓶牛奶还剩半升。

There's only half a ___litre of milk left in this bottle.