64seconds _% Y, V. v+ @( r4 G0 T- w
) X; ]. W' M5 Y! otvb now,tvbnow,bttvb1 to 4 have 3floors = 48 sec& v; z L' f5 E/ X e& Q& V
avg. 48/3 = 16sec公仔箱論壇! u" M9 B* ?) a
. Z2 p/ ^! l# t公仔箱論壇4 to 8 have 4floors = 16x4公仔箱論壇2 b1 V; @2 |8 f$ z2 `9 u2 G
= 64secs |