To stabilize its population—discounting immigration—women must have an average of two children.

为了稳定人口——减轻移民的影响——妇女必须平均生育两个孩子。

youdao

We can readily calculate that a population with a mean brain size of 1, 750 cc would be expected to have an average IQ of 149.

通过计算我们可以得出，一个脑容积平均为1750cc的种族，其平均智商将为149。

youdao

That translates to an annual drop of about 1 percent of the average plankton population between 1899 and 2008.

这意味着自1899年至2008年之间，浮游植物的数量平均每年减少约百分之一。

youdao

Is that right, Jared, in an average year for our population?

WHITEHOUSE: Online Town Hall

If people in this population meet and breed at random, it turns out that you only need to go back an average of 20 generations before you find an individual who is a common ancestor of everyone in the population.

BBC: Family trees: Tracing the world's ancestor

But Yeovil, an area of similar population size with a faster average broadband speed, clocks up a monthly average of 4, 259 downloads.

BBC: A glimpse at piracy in the UK and beyond