He has come to be recognized as an expert in the problem of overpopulation and food supply.
由于他的经验促使他终于成为了公认的人口过剩和食物供应问题的专家。
Meanwhile, a microphone, which was lowered into the mine two hours ago, has enabled the men to keep in touch with their closest relatives.
与此同时,两个小时以前放下井去的一只麦克风使井下的人可以与其亲属保持联系。