例句：

　　1、A day is about one thirtieth of a month.

　　一天大約是一個(gè)月的三十分之一。

　　2、One second of arc movement is one thirtieth of a millimetre.

　　一弧秒的移動(dòng)是一毫米的三十分之一。

　　3、The current contract with the actors union ends June thirtieth.

　　目前其與演員工會(huì )的合同將在六月三十結束。

　　4、The last day in September is the thirtieth.

　　九月的最后一天是三十日。

　　5、Thirty-three thousand people think that Thursday is their thirtieth birthday.

　　三萬(wàn)三千人認為星期四是他們三十歲生日。