It has always been the of our firm to encourage workers to take part in social activitie

问题补充：

It has always been the of our firm to encourage workers to take part in social activities.

A. plan

B. campaign

C. procedure

D. policy

答案：

A. plan

B. campaign

C. procedure

(答案→)D. policy

解析：本题译文：本公司的一贯方针是鼓励工人参加社会活动。policy(尤指政党、政府、大企业、商行等的)政策，方针。Campaign(政治或竞选的)运动；（军事的）行动，procedure做事的手续、程序，rule规则，plan计划，均不合题意。