So much so he taught himself French and English all by the age of 6.

所以他在6始自学法语和英语了。

By the age of 14, he was fit enough to pose for anatomical charts.

在十四时，他已经够健壮到能当人体结构图的模特儿。

By the age of three, he was able to read.

到三时，他已经识字了。

Each Indian of the Great Plains could ride a horse by the age of five.

大平原地区的每个印第安人五始骑马。

This give-and- take allows them to use fluent sentences by the age of four.

这种“输入并输出”的方法让人类儿童在四时能使用流利的。

The actor achieved fame by the age of 22.

那位演员22时成名了。

For both girls and boys, it is usually complete by the age of 18.

无论男孩女孩，通常都到 18 完成（青春期）。

Baldness affects approximately half of men worldwide by the age of 50.

全球大约有一半的男性在50时秃顶。

By the age of sixteen, Frank had ditched school altogether.

法兰克16的时候辍学了。

He had mastered both integral and differential calculus by the age of 15.

他在15时已经掌握了微积分。

By the age of twenty-five, I had managed to get married ... and also divorced.

25时，我不仅完成了结婚这件大事，也经历了离婚。

Blood tests indicate that most children have had it by the age of 5.

血液测试表明，大多数儿童在5时患有此病。

By the age of 14, he was playing internationally.

到14时，他始在国际上下棋。

For both sexes, it is usually complete by the age of eighteen.

男孩和女孩通常在18结束青春期。

Do you know he was a multimillionaire by the age of 35?

你知道他在35时已经千万富翁了吗？

By the age of seven, children are capable of thinking in abstract terms.

【abstract】儿童到了七具有抽象思维的能力。

One patient, who began puberty blockers aged 12, suffered four fractures by the age of 16.

一名患者在12时始服用青春期阻断剂，16时发生了四次骨折。

By the age of 12 nearly every child has a phone, according to research in Britain.

英国有研究表明，到12时，几乎每个孩都拥有一部手机。

The study challenges the commonly held notion that intelligence is 'static' by the age of about 18.

人们普遍认为，智商到了18左右“静止”了，此研究否认了这个说法。

By the age of three, a child's brain has twice as many synapses per neuron than in adults.

到三时，儿童大脑中每个神经元的突触数量成年人的两倍。