(1) As predicted by scientists， global polulution has became one of the most serious problems that humankind is facing.

时态：现在完成时，“最严重”用最高级

(2) Competition for these pasitions is tough very much,and the year's applicants are five times as high as last year's.

five times 5倍 position 职位

(3) As the fact shown, the educational programer should fit into national plan for economic development.

符合：fit into. 教育大纲：educational programer

(4)  The car is burn too much gas,morever, the price is almost twice what I want to pay.

burn too much gas 费油

(5) In order to understand a major intemational event, we firstly need to consider its historical and political background.

国际事件 international event