Sentence:  Give them food , some shade , mulch , <WSD>water</WSD> and more food , and they 'll repay your solicitude with beauty . 
Meaning of the word marked with <WSD> tags:  binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent