1、 At first,bartering took place asan exchange between two people.
起初，物物交换是发生在两个人之间的交易。
来源:
2、 PercySpencer, an engineer at Raytheon after his WWI stint in the Navy, was known asan electronics genius.
第一次世界大战期间，珀西·斯宾塞曾在海军服役。 战后，这位工程师就职于雷神公司，他是电子方面的天才。
来源:
中