在会场中有5个人，每两个人必须握一次手，那么所有的人总共握了多少次手?
A、5*4*3*2*1Thefirstparagraphisintendedto________.
As____clearfromhismanners,heisateacher.
U.S.News____________rankingsofcollegessince1983.Theyareaverypopularresourceforstudentslookingtoapplytouniversitycampus.
ProfessorJohnsonissaid_____somesignificantadvanceinhisresearchinthepastyears.
Whiledoingcalculationfortheproject,thedesigners____anewsolutiontoageologicalproblem.
