Question

He is rather difficult to make friends with, but his friendship, _____ is more true than anyone else’s.

A．Once gaining

B．Once gained

C．Once is gaining

D．Once he gained

Answer 1

B

试题分析：这题考察条件状语从句，当主从句的主语一致时，可以省略从句的主语和be动词，once gained="once" his friendship is gained，选B。
点评：考查条件状语从句的省略，主要要看清主语是否一致，再考虑主动和被动关系。