单选题Mr. Wang decided to 

问题补充：

单选题Mr.Wangdecidedtodevoteallhistime_______hisspokenEnglishbeforegoingabroad.A.improveB.to improveC.improvingD.to improving

答案：

D解析本题考查devote的用法。devote sth to doing sth 把…献给做某事；devote oneself to doing sth 献身于做某事。