The average contributions of penta-CBs to the total atmospheric PCBs were similar between suburban and background area, with values of 9.65% and 10.87%.是什么意思_The average contributions of penta-CBs to the total atmospheric PCBs were similar between suburban and background area, with values of 9.65% and 10.87%.在线翻译_英语_读音_用法_例句