1. fertility rate 生育率
例句:"The fertility rate will naturally go down with a better economy and a greater passion for education," Liang said.
“经济状况好转,热衷教育,生育率会自然下降,”梁中堂说 。
2.time bomb 定时炸弹
例句:It is a ticking time bomb for the federal budget.
对于联邦预算而言,过高的医疗费用就像一枚定时炸弹 。