送交者: skipper3 于 2005-6-07, 13:32:04:
回答: I went to see someone here in the States. He's on 13th. Regular office. 由 Enlighten 于 2005-6-07, 13:24:49:
the architect told me skyscrapers usually take big pressure from the wind. Leaving one floor open in every several floors will help to release such pressure therefore reduces construction cost. It is very convenient to use 13th for that purpose.