【简答题】With the world’s population estimated to grow from six to nine billion by 2050, researchers, businesses and governments are already dealing with the impact this increase will have on everything from f...
【单选题】World population will continue rising from the current 5 billion until about 2050, but if the trends of the 1980s continue, it will ______ at about 9 billion.
【简答题】听力原文:By 2050, 25 percent of all Americans will be older than 65, up from 14 percent in 1995. The change poses profound questions for government and society. But it also creates career opportunities in...