In 1920 the rings were revived to represent the five continents with North and South America being represented by one ring.
1920年,这些环重新被用来代表包括五个大陆,南北美洲用其中一个环表示。
Although city officials would not comment on how many bids were received by today's 4 p.m. deadline, five groups announced that they had jumped into the ring.
虽然官方没有透露今天下午4点竞标截至时参与竞标的团队数目,但有5个团队已经宣布他们参与了竞标。
The five quinazoline compounds were prepared by using 2 amino 4,5 dimethoxy benzoic acid as original material, which underwent ring closing, halogenation and substitution.
方法:以2 氨基4 ,5 二甲氧基苯甲酸为原料,分别经过环化、氯代、取代等反应,合成了五种目标化合物。
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