13. We would like to make advance arrangements for client conferences.
我们希望事先安排与客户洽谈相关事宜。
还能这样说：
We want to make an arrangement for the client conference in advance.
We are desirous of arranging for the client conference ahead of time.
应用解析：
advance in sth. 在某方面改进；
advanced level 高级水平；
advance sth. to sb. 向某人预付（钱），借（钱）；
advance towards sth. 向着某物前进

14. We should phase in the new working plans.
我们应逐步采用这个新的工作计划。
还能这样说：
We should put this new working plan into practice step by step.
We ought to adopt the new working plan gradually.
应用解析：
phase in 逐步采用，逐步引入；
phase out 逐步停止采用，逐步退出；
phase sth. out 逐步或分阶段撤出或淘汰

15. We must make our company known to more and more people in the world.
我们必须让公司为世界上越来越多的人了解。
还能这样说：
We must make our company popular in the whole world.
We spare our efforts to make our company known by more and more people.
应用解析：
world without end 永远；
be all the world to sb. 对某人来说非常宝贵或非常重要；
go up in the world 发迹，变富；
dead to the world 熟睡；
for all the world 无论如何