Many phrasebooks remained in use for a surprisingly long time.

许多常用语书流传了很长时间。

To sift through old phrasebooks is to study an unparalleled source on the assumptions made by Britons abroad.

旧时的常用语手册是一些独一无二的材料，能够用于研究旅居海外的英国人对当地产生的猜测。