例句：David created his own company when he was thirty.
翻譯：David 在他三十歲時開創了他自己的公司
變化
● 單數：thirty [ˋθɝtɪ]
● 複數：thirties [θ'ɚtiz]
例句：Mom, please give me thirty dollars.
翻譯：媽媽，請給我三十元。