This change in morphology is associated with important physical and cytochemical changes and with an increase in their capacity for motility and their fertilizing ability. 這種形態(tài)學(xué)的變化是與重要的物理學(xué)和組織化學(xué)的變化以及活力和受精能力的增強有關(guān)。
When it is not, then availability of IVF depresses the birth rate because women balance the cost of a child against the extra income they could earn in employment outside the home. 當它得不到巨額補助的時(shí)候，試管受精便使生育率越發(fā)低下，因為婦女會(huì )對生育孩子的成本和她們在外受雇所掙的額外收入進(jìn)行比較。
