late 14c. metathesis of thritti, from Old English þritig, from þri, þreo "three" (see three) + -tig "group of ten" (see -ty (1)). Similar formation in Old Frisian thritich, Old Saxon thritig, Dutch dertig, Old High German drizzug, German dreissig.
The Thirty Years' War (1842) was a religious power struggle waged 1618-48, mainly on German soil. The symbol -30- as printer and telegrapher's code to indicate the last sheet or line of copy or a dispatch is recorded from 1895. In 20c. jargon of newspaper journalism, it came to be a traditional sign-off signal and slang word for "the end."
实用例句
1. By 1973 the government deficit equalled thirty per cent of GNP.
到1973年，政府财政赤字相当于国民生产总值的30%。
来自柯林斯例句
2. I know that you'vebeen studying chimpanzees for thirty years now.
我知道你研究黑猩猩至今已有30年了。
来自柯林斯例句
3. Thirty seconds later she reappeared and beckoned them forward.
30秒后她又出现了，示意他们往前来。
来自柯林斯例句
4. The price of a single ticket is thirty-nine pounds.
单程票的价格是39英镑。
来自柯林斯例句
5. They walked through the dense Mozambican bush for thirty six hours.