A 78-year-old client with sensorineural hearing loss is admitted to a rehabilitation center after hip replacement surgery. A risk factor for this client would be

A. altered perceptions.
B. toxic levels of pain medication.
C. impaired cognitive function.
D. impaired sense of tim

如图是小球沿斜面滚下的频闪照片，照片中每两个相邻小球的像的间隔对应的时间都是0.1s，这样便记录了物体运动的时间。物体运动的位移可以用直尺测量。试作出小球沿斜面滚下的v-t图象。