本题目来源于试卷: Overweight and underweight，类别为 美国物理杯赛(Physics Bowl)
[单选题]
07.13: Astudent weighin m+ccg aqo3xkq b69*0ug 5y has ;lhmi-m48 h-ru,00 N stands on a bathroom scale in the school’s elevator. When the scale reads 520 N, the eleva4ysl -ir;h, -mmua h8htor must be
A. accelerating upward.
B. accelerating downward.
C. moving upward at a constant speed.
D. moving downward at a constant speed.
E. at rest.
参考答案: A
本题详细解析:
暂无
| 
