Don’t touth anything unless .
A. to be allowed
B. allowed
C. to be allowing
D. allowed to
网友回答
A. to be allowed
(答案→)B. allowed
C. to be allowing
D. allowed to
解析：句意：不要触摸任何的东西除非被允许。这里用了状语从句的省略。完整的句子是：unless you are allowed to touch，当主从句的主语一致的时候，可以省略从句的主语和be动词，选B。