标题: 求教 og 12 sc 8 [打印本页] 作者: flow123flow 时间: 2011-10-21 16:40 标题: 求教 og 12 sc 8 the widely accepted big bang theory holds that the universe began in an explosive instant ten to twenty billion years ago and has been expanding ever since.
请问 ten to twenty billion years ago 是什么意思？ 关键是 这个to 不太清楚。 谢谢！作者: cxroger 时间: 2012-11-4 23:26
100 至 200 亿年