测量误差按性质分为()。
A.系统误差
B.随机误差
C.测量不确定度
D.最大允许误差
参考答案:A, B
—Could you tell me yesterday?
—Because my bike was broken on my way here.
A.why you came late
B.why do you come late
C.why you come late
D.why did you come late
下列哪个说法是正确的?
A.体操运动员双手握住单杠吊在空中不动时处于失重状态
B.蹦床运动员在空中上升和下落过程中都处于失重状态
C.举重运动员在举起杠铃后不动的那段时间处于超重状态
D.游泳运动员仰卧在水面上静止不动时处于失重状态