infant mortality (ie The rate at which babies die) was 20 deaths per thousand live births in 1986.
1986年的婴儿死亡率为生育成活率的千分之二十.
infant mortality is still very high in some developing countries.
某些发展中国家的婴儿死亡率仍然很高。
She gazed at the newborn infant and smiled.
她望着这个初生的婴儿笑了。