Mr. Jones is a renowned international authority on the problem of overpopulation in developing countries.
琼斯先生在发展中国家人口过剩问题方面是声誉卓著的国际权威。
Between 1850 and 1910 the bison population is thought to have fallen from 60 million to just a few hundred.
人们认为,在1850年到1910年之间,野牛的头数从6,000万头降到只有几百头了。