The story tells ____ that love is the most expensive present in the world.
A:we
B:us
C:our
D:ours
已知递减的等差数列{an}满足a12=a92,则a5=( )
在行驶的卡车内,看到吊饰向前摆动,卡车应在 ____(选填“加速”、“减速”或“匀速”)行驶.当卡车速度计指针如图所示时,车速为 ____km/h;按此速度匀速速行驶360km,所需时间为 ____