Nine is usually thought of as a lucky number because it is the product of three times three.

9通常被认为是一个幸运数字，因为它是3乘以3的乘积。

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At this rate they'd be lucky to get home before eight-thirty or nine.

照这样下去，他们能在8：30或9：00前到家就很走运了。

《柯林斯英汉双解大词典》

Nine is just lucky all around!

数字9简直是幸运满满！

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"I could just be lucky, but lucky nine years in a row isn't bad, " he says.

FORBES: Magazine Article

The Hammers were lucky not to be reduced to nine men after Chilean Javier Margas cynically cut down the Frenchman, failing to receive even a yellow.

BBC: Lomas off in bore draw