You focus on the concept of a drop of water, and you say: first drop, second drop.

If it is determined in said second-level determination that a water drop is present, a water-drop removal unit (20) removes said water drop from the imaging window (10W).

A glass can exist without water but a glass of water cannot.

A steady drip of hot water can waste many gallons of water...

At that moment the drop of water is no longer a drop of water,

This is not just a water event; this is a bunch of sludge.

The generally planar neck opening can be teardrop shaped.

This is not just a water event; this is a bunch of sludge.

One drop of water is made up of thousands of water molecules.

A drop in the budget bucket, perhaps, but powerfully symbolic.

A tiny drop of water is made up of thousands of molecules of water.

One drop of water is made up of thousands of water molecules.

A tiny drop of water is made up of thousands of molecules of water.

It's a sad situation, and what I have done is only a 'drop in the ocean' but every drop counts!

A drop of water meets a drop of oil and they start dancing.