To prepare a pesticide, 1 part of medicine and 2000 parts of water. How many kilograms of water are needed to prepare 4002 kilograms of this potion?
配制一种农药，药占1份，水占2000份．要配制这种药水4002千克，需要多少千克水？
<gadget id="calculator">2_000 / 2_001</gadget>
<output>2_000/2_001 = around 0.9995</output>

<gadget id="calculator">4_002 * (2_000/2_001)</gadget>
<output>4_000</output>

<result>4_000</result>