Directions: In this section of the test, there are ten paragraphs. Each of the paragraphs is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Spell out the missing letters of the word on your Answer Sheet.
Paragraph One
Rising temperatures in a warming world will cost poor countries tens of billions of dollars annually as they are less able to keep their workers cool, analysts said on Thursday. By examining energy infrastructure with temperature data and projected urban population growth, researchers said workers in Africa and Asia would be most affected by rising heat.
Rising heat to c_____ rising cost.
【正确答案】：cause
