GreatasNewtonwas,manyofhisideas____todayandarebeingmodifiedbytheworkofscientistsofourtime.
C
【句意】尽管牛顿非常伟大，然而他的许多观点当前正受到怀疑，并且当今的许多科学家正在努力对这些观点进行修正。
【难点】challenge意为“挑战，怀疑”，常用作及物动词。本句中牛顿的观点受到挑战为一个当前已经发生的事实，故采用现在完成时的被动语态。
Thereis______littleinformationabouthimthatwehave______muchdifficultyfindinghim.
______ they are twin sisters, they don ’t look like each other.
—Icametoyourofficeyesterdaymorning,butnobodywasin.
—Oh,we__________ameetinginthemeetingroom.
Rumors are everywhere, spreading fear,damaging reputations, and turning calm situations into ____ ones.
My coat__________ there behind the door. Can ’t you see it?