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。
If there is one -- which I take leave to doubt -- then it is older people who create it, not the young themselves.
如果这个问题存在的话 -- 请允许我对此持怀疑态度 -- 那么,这个问题是由老年人而不是青年人造成的。