Measure the depth of the water with a bamboo pole. The part above the water is 120 centimeters long, which is 20 centimeters less than twice the part submerged in the water. How deep is the water in centimeters?
用一根竹竿测水深，露出水面部分长120厘米，比浸没在水中部分的2倍少20厘米，水深多少厘米？
<gadget id="calculator">120 + 20</gadget>
<output>140</output>

<gadget id="calculator">140 / 2</gadget>
<output>70</output>

<result>70</result>