九十的英文：
ninety

She's already ninety.
她都九十岁了。

He must be going on for ninety.
他准有九十岁了.

Tim McGraw debuted in the early 90's.
蒂姆·克劳出道于上世纪九十年代初。

Ninety per cent of inspiration is perspiration.
百分之九十的灵感是汗水。

An angle of 90°is called a right angle.
九十度角称为直角。

My grandmother is now past ninety
我祖母已过九十。

Your grade was in the nineties.
你的分数是九十几分。

Over ninety percent of the islanders here are illiterate.
"这儿的岛民,百分之九十以上都是文盲。"

In the past up to 90% of black people lived in the South.
过去百分之九十的黑人居住在南部。

Well over ninety out of every hundred of these counter-revolutionaries should be dealt with in this way.
一百个反革命里面，九十几个这样处理。

Your grade was in the nineties.
你的分数是九十几分。

Ninety per cent of inspiration is perspiration.
百分之九十的灵感是汗水。

He was born in the nineties of the nineteen century.
他生于十九世纪九十年代。

Over ninety percent of the islanders here are illiterate.

For the use of ninety and ninetieth see the examples at five and fifth
关於ninety和ninetieth的用法见five和fifth词条中的示例