Two teams of migrant workers dig a canal from places A and B at the same time. When the first team has dug the full length of the canal (5/14), the second team has just dug half of the canal, and there are 120 kilometers left. The canal is dug through. If the second team digs the canal alone at a speed of 70 kilometers per day, how many days will it take to finish digging?
两队民工从甲、乙两地同时挖一条水渠，第一队挖完水渠全长的(5/14)时，第二队正好挖完这条水渠的一半，还剩120千米，这条水渠就挖通了，如果第二队以每天70千米的速度独挖这条水渠，需要多少天挖完？
<gadget id="calculator">5 / 14</gadget>
<output>5/14 = around 0.357143</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (5/14) - (1/2)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">120 / (1/7) / 70</gadget>
<output>12</output>

<result>12</result>