The actor achieved fame by the age of 22.

那位演员22岁时就成名了。

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

全球大约有一半的男性在50岁时秃顶。

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

男孩和女孩通常在18岁结束青春期。

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

你知道他在35岁时已经是千万富翁了吗？

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

法兰克16岁的时候就辍学了。

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

在十四岁时，他已经够健壮到能当人体结构图的模特儿。

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

所以他在6岁是就开始自学法语和英语了。

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

无论男孩子还是女孩子，通常都是到 18 岁完成（青春期）。

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

25岁时，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岁时就患有此病。