His son is twenty-one years old.

他的儿子21岁了。

We waited twenty-one years, don't fail us now.

我们等了21年 如今不要辜负我们

Twenty-one people died, five of whom were students.

事故造成21人死亡，其中5人为学生。

He was stricken at twenty-one with a crippling malady.

二十一岁时腿瘸疾病让他受到重击。

I was twenty-two – no, twenty-one.

我那时22岁。—噢不，21岁。

We waited twenty-one years, don't fail us now.

我们等了21年，如今不要辜负我们。

The government implemented a rule that the guinea is worth twenty-one shillings.

政府实施了一项规定，即一几尼价值21先令。

Open your book at Page twenty-one.

把书翻到第二十一页。