A:x=40
B:x=15
C:x=14
D:x=0.6
小明想把重1000N的木箱A搬到高h=5m,长L=10m的斜面上,如图所示.他站在斜面上,沿斜面向上用F=600N的拉力使木箱A以v=0.2m/s的速度匀速从斜面底端拉到斜面顶端.求:
Anna didn't see the movie last night because she ____ already ____ (see) the film.