— What kind of music do you like best?

— I like the music _____ is quiet and gentle. [ ]

A. who

B. that

C. whose

D. where

一条河宽400m，水流的速度为2.5m/s，船相对静水的速度5m/s，要想渡河的时间最短，渡河的最短时间是______s；此时船沿河岸方向漂移______m．