A:1对
B:2对
C:3对
D:0对
Sara walked in fear, because she felt that someone was following her.
“两岸猿声啼不住,轻舟已过万重山”描述的是( )
质量 0.8 kg的小球被抛出去后,如不计空气阻力,则小球受到重力的大小是____ N,力的方向是____.(g=10N/Kg)