360. The outbreak of the Second World War was quickly followed by an increase in the number of day nurseries in almost all countries, as women were again called upon to replace men in the factories.
随着二战的爆发，妇女们又被召去工厂以填补男性劳动力的缺失，紧接着几乎所有国家的日托数量都有所增长。

六级词汇讲解:
本句的主干是The outbreak...was...followed by...，向as…是原因状语。call upon=call on意为“号召，要求”。可构成以下搭配：call upon sb. to do sth.（号召某人做某事）、call upon sth.（要求某事）。replace意为“取代，代替”，一般多采用被动态，即sb./sth. be replaced by...。

英语六级考点归纳:
关于call的短语除了call upon之外，常见的还有：

call for意为“寻求，需要”。如：
More work does not necessarily call for more men.
增加工作不一定需要增添人员。

call up意为“打电话；使想起”。如：
It called me up those days when l was young.
这些让我想起了年轻时的日子。

call forth意为“引进，唤起；振作起”。如：
His inspiring speech has called forth admiration from all the people presented.
他那鼓舞人心的讲话引起了所有在场人的赞赏。