1.As predicted by scientists, global pollution has become the most serious problem that mankind has faced.
2.Competition for these positions is fierce —— there are five times as many applicants this year as last.
3.As the facts show, the educational program should fid into the country's economic development plan.
4.The car burn too much gas，moreover costs almost twice what I wanted to pay.
5.To understand a major international event we first need to consider its historical and political background.
