年平均的英文：
mean annual

参考例句：

The annual average (growth) index has reached 45%.
年平均指数达45%。

The annual average temperature here is 24 degree celsius.
这里的年平均气温为24℃。

What is the average annual rainfall in this region?
这个地区的年平均降雨量是多少

The average yearly increment in productivity was 4.5 percent.
生产率的年平均增长量是4.5%。

The mountains rejoice in an average annual rainfall of thirty inches.
山区的年平均降雨量为30英寸。

The average snowfall here is 10cm a year.
这里年平均降雪量为10厘米.

Rainfall this year exceeded the yearly average.
今年的雨量超过了年平均降雨量。

Washington will average 450 million boxes in the 1970's with an up of 50 million boxes every year.
七十年代华盛顿州年平均产量将达到四亿五千万箱，每年上升达五千万箱产量。

mean是什么意思：
v. 想要；意欲；意味着；预定
adj. 自私的；卑鄙的；平均的；低劣的；低微的，卑贱的
n. 中间；平均数，平均值

That was a mean trick!
那是卑鄙的诡计！

A modifier that has little meaning except to intensify the meaning it modifies.
修饰语除了加强修饰词的意思之外没有实际意义。

get money by dishonest means
非法赚钱, 得不义之财

The meaning of the passage is obscure.
这段文字意义晦涩。

No stutter, maybe, but lots of mean.
不口吃，也许。 但是很恶毒。

annual是什么意思：
adj. 每年的，年度的；年生的
n. 年刊，年报，年鉴；年生植物

multiple (double) annual ring
复年轮

annual ring density
年轮密度

He endows this university annually.
他每年都会资助这所大学。

Companies report to their shareholders annually.
各公司每年向其股东汇报一次。

The Association holds an annual reunion.
这个协会每年聚会一次。