The snowstorm added to our difficulties.为什么要加to,add是及物动词呀

The snowstorm added to our difficulties.为什么要加to,add是及物动词呀 He___(freeze)while waiting for the bus during the snowstorm His father died in the snowstorm last year 同义句The snowstorm ______ _____ ______ last year His father _______ _______ ______ in the snowstorm last year nothing __ our understanding of the math problem 应填added/added to/added up to/added up? his report has greatly------our knowledge of the subject.A.added B.added to C.added upD.added up to 49.10his jokes at the wedding___the joy and happiness of the occasiona.were added tob.added up toc.added tod.were added in 高一英语28He said that the Giant Apple （ ） the beauty of our school.A added B added to C added up D added up to The money we spent on the new project in beijing ( ) 8 million RMB.A added B added to C was added up D added up to The money he spent ____ more than $5,000.A.added B.added up to C.added to D. The money _________ no more than 50 dollars.(A) added(B) added up(C) added up tp(D) was added to并说明理由 What he said about the incident and done with it_______our troubleA.added up to B.added to C.added up D.were added to Many words and phrases have been ________ this newly revised edition of the dictionary．A.added up to B.added to C.added up D.added in his report has greatly------our knowledge of the subject.A.added B.added to C.added up D.added up to They received the snowstorm waining the day before,and got everything ready for it(英译中） the heavy snowstorm made the moutain climbera______halfway.a stop b to stop c stopping d stopped the bad weather only__our difficulties to arrive there on time.为什么不是added 而是added to the great wall has been_several times.A.added B.adding to C.added to D.the great wall has been_several times.A.added B.adding to C.added to D.added in Because of the snowstorm,some trees and house were destroyed in Hengyang.改成一般疑问句