现把楼主和4楼的问题合在一起:
1) 2 7/8"
2) An
3) 根号3
4) 套管尺寸:9 5/8"
5) 油管尺寸:3 1/2"
综合归纳一下,供参考:
1) two and seven eighth inches, or two feet and seven by eighth inches
2) A to the power N, or the Nth power of A
3) the cubic root of
4) nine and five eighth inches, or nine feet and 5 by eighth inches
5) three and a half inches