只需要很小的一滴就可以了。It's only necessary to use just a very small blob.我一滴眼泪也没掉。I didn't shed a single tear.他从瞎了的眼睛里擦去了一滴泪水。He wiped a tear from his sightless eyes....

“一滴”的英语可以翻译为：lob，drib，gout，minim，glob ...