平均起来...

On average each report requires 1,000 hours to prepare.准备一份报告平均需要1,000小时。Every tonne of coal contains, on average, 30 kilograms of nitrogen.每吨煤平均含30公斤氮.We received 20 calls a day on average.我们平均每天接到二十个电话....

on average的音标：on average的英式发音音标为：[ɔn 'ævəridʒ]on average的美式发音音标为：[ɑn 'ævərɪdʒ]...