人类探测月球发现，在月球的土壤中含有较丰富的质量数为3的氦，它可以作为未来核聚变的重要原料之一．氦的该种同位素应表示为（　　）

A．₃⁴He

B．₂³He

C．₂⁴He

D．₃³He

So we have focused on strategic areas where we can make the biggest impact on agricultural change that stretch from the farm to the market to the table and keep people nourished and productive, health systems that help people spend their days working rather than sick or dying, opportunities for women and girls that allow them to contribute to economic and social progress.