单选题Mr. Smith__________ the r

问题补充：

单选题Mr.Smith__________therolloffilmassoonashearrivedhomeA.got down to washB.got down to developC.got down to washingD.got down to developing

答案：

D解析此题考查的是固定词组，get down to后可直接接名词或动词-ing形式。