后处理器插件方法有点更难于掌握，但是比上下文变量方法更强大。
The post-processor plug-in approach is a bit more difficult to master, but more powerful than the context variable method.
他们认为图书馆技术要比联机检索主题知识更难于掌握。
They rate librarianship skills higher than subject knowledge in on-line searching.
游击队的主动权，在敌人举行数路围攻的场合，是难于掌握和容易丧失的。
When the enemy is making a converging attack from several directions, a guerrilla unit can exercise initiative only with difficulty and can lose it all too easily.
应用推荐