第 (dì): 序数の接頭辞; 序数の接頭辞; 例：第一「first」、第二「second」; （几の前に）どの（順番で）; 例：第几「which number?」

This is my first time coming to China.

He lives in the second room on the third floor.

Lesson three is difficult but very interesting.

Please turn the book to page ten.

He lives on the third floor.

You are in the ninth position.

How many times have you been to Beijing?