64seconds
" i F. o4 d6 [. c8 C& B
/ P# w4 r. i' U# n4 K$ E& b公仔箱論壇1 to 4 have 3floors = 48 sec
6 G* n1 o: u0 mavg. 48/3 = 16sec
7 U; V: m9 i# [8 ~' j# Etvb now,tvbnow,bttvb2 z9 p! x: J8 {. \. N: R
4 to 8 have 4floors = 16x4
. Z, ?! ]5 p' c8 C= 64secs |