If you want to get this job,  you should_________ speak a foreign language.   [ ]

A. at last                    

B. at most  

C. at least                    

D. at all

阴疮多因＿＿、＿＿、＿＿而成，其治疗原则应按＿＿ 、＿＿、＿＿、＿＿、＿＿、＿＿的原则处理。