题目

She devotes as much time as she could __________ the patients. A. to saving  B. to save                C. saved                D. in saving 答案：A某人用力抬起放在水平地面上的一匀质杠杆的B端，F始终与直杆垂直，如图所示，则在抬起直杆的过程中（　　）A．F逐渐变大B．F逐渐变小C．F保持不变D．无法确定