Among the three fractions (2/9), (4/7), and (2/7), what is the largest one?
在(2/9)、(4/7)、(2/7)这三个分数中，最大的一个是多少．
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<result>4/7 = around 0.571429</result>