雅思考试必背高频词组短语 an average of
释义：
an average of 平均是…
例句：
Parents spend an average of $220 a year on toys.
父母为孩子买玩具的花费每年平均为220元。
Johnson carried the ball an average of 6 yards per rush.
约翰逊跑动带球平均每次行进6码。
Kelly had scored an average of 147 on three separate IQ tests.
凯利在3次单独进行的智商测试中平均得到147分。
In the autumn of 1940 London was blitzed by an average of two hundred aircraft a night.
1940年秋，伦敦平均每晚被两百架飞机空袭。
Doctors work an average of 90 hours a week, while a few are on call for up to 120 hours.
医生们平均每周工作90个小时，而有些出诊长达120个小时。
At all 14 state schools, tuition and fees are going up this autumn by an average of about 10 percent.
所有14所州立大学今年秋季的学杂费都将上涨平均约10％。
Gasoline now costs an average of $3.15 a gallon, seven cents shy of the record set last May.
汽油现在的平均价格是每加仑3.15美元，仅比去年五月的记录低了七美分。
Between 1969 and 1989 employed Americans added an average of 138 hours to their yearly work schedules.
在1969年至1989年期间，美国人的年度工作时间平均增加了138个小时。
Tips on these bills were an average of three percentage points higher than tips on bills without the message.
这些账单上的小费比没有信息的账单上的小费平均高出3个百分点。
Altogether the volunteers logged 433 unintentional actions that they found themselves doing—an average of twelve each.
志愿者们一共记录了433件他们发现自己在无意中做的事情——平均每人12件。
Car owners who rent their vehicles to others using RelayRides make an average of $250 a month; some make more than $1000.
通过RelayRides 将汽车出租给他人的车主平均每月收入为250美元；有些人的收入超过1000美元。
With costs falling and kitchen appliances becoming "status" items, owners are throwing away microwaves after an average of eight years.
随着成本的下降和厨房电器成为“身份”物品，业主平均在使用了八年之后就把微波炉扔掉了。
A study published in the New England Journal of Medicine estimated that there are an average of 30 in-flight medical emergencies on U.S. flights every day.
在《新英格兰医学杂志》上发表的一项研究预估，美国飞机上每天平均会发生30起机内医疗紧急事件。
Involvement in sports, in particular, rose almost 50% from 1981 to 1997: boys now spend an average of four hours a week playing sports; girls log half that time.
特别是参与体育运动，从1981年到1997年上升了近50%：男孩们现在平均每周花四个小时做运动；而女生则只花一半的时间。
In 1981 children in the United States spent an average of slightly less than two and a half hours a week doing household chores; by 1997 they had spent nearly six hours a week.
1981年，美国儿童平均每周花在家务上的时间略少于两个半小时；到1997年，这个时间达到近6个小时。
Energy is an essential resource across the entire food production cycle, with estimates showing an average of 7-10 calories of input being required in the production of one calorie of food.
在整个食品生产周期中，能量是一种必不可少的资源，据估计，生产一卡路里的食品平均需要7-10卡路里的投入。
For the farmer who takes care to keep them cool, providing them with high-energy feed, and milking them regularly, Holstein cows are producing an average of 2,275 gallons of milk each per year.
对于那些照顾它们保持凉爽，给它们提供高能量饲料和定期挤奶的农场主来说，荷尔斯坦奶牛平均每年能产2275加仑的牛奶。
Those only repeating words performed the same as those with no distraction, but those with the more complicated task showed even worse reaction times—an average of 480 milliseconds extra delay.
那些只复述单词的人与那些不分散注意力的人表现得一样，但那些任务更复杂的人反应时间更差——平均多出480毫秒的延迟。