And the traditional preference for boys sometimes leads to selective abortion, causing worries over the imbalance of gender ratio.
想要男孩的传统偏好导致许多人选择堕胎，这就造成了大家担心男女比例的失衡的问题。
2
Countermeasures: fair use, temperance drug use, develop the risk-benefit ratio, low residue and selective pesticides.
对策：公道用药，节制用药，研制高效低毒，低残留并有选择性的农药。
3
Selective suitable conditions such as the ratio of reactions, different catalyst and the addition of dehydrater etc are presented. The result which is the yield of product is 82.5%.