Fact 1: If an object in a fluid is more dense than that fluid then that object will sink in that fluid because of gravity.

Fact 2: Water is usually the best fluid.

Given the two facts above, answer the question "an object will sink in what if it's more dense?" with the following options: 
- water
 - gravity
 - calcite
 - wood
 - liquid
 - rain
 - outer space
 - crust


 

 water        