别做慈善家
正转反转的英文是Forward rotation and reverse rotation。
例句：
1、以四相步进电机为例，介绍了由MC1413驱动的电路原理图，给出了四相步进电机的正转反转的程序设计流程图和程序清单。
Taking a four-phase step-by-step motor as example, this article introduces the electrical circuit schematic diagram driven by MC 1413.It also presents the motor's clockwise and counter-clockwise programming flow chart and detailed list.
2、采用PLC的高速计数器进行测量轮正转和反转时的脉冲信号的采集，通过进一步程序运算得到绝对位移量。
The pluses comes from coder to send to the high speed counter, and the number of the high speed counter is operated in the program of PLC to get the absolute displacement anticipated.
3、ZPB遥控按钮盒供远距离控制各种电器设备的启动、正转、反转、紧急停止及风油切断等用处，并通过指示显示工作状态。
ZPB Remote Button Box use of far distance control start, stop, emergency stop and shut off fans& oil pumps of various kinds of electrical equipment and display working state by indicator.
4、洗涤和漂洗都是通过控制电机的正转和反转来达到清洗衣物的主要目的。
Cleaning and flushing the motor through the control of forward and reverse, to reach the main purpose of washing clothes.
5、采用有限元法解雷诺方程，研究了双向人字槽液体润滑止推轴承的承载力、轴向刚度系数和阻尼系数，并与相同参数下正转、反转的单向人字槽止推轴承进行比较。
Finite element method is employed to solve Reynolds equation and investigate dynamical performance of two way herringbone grooved liquid lubricated thrust bearing ( HGTB).
珍妮爱美食
正转的英文：Forward rotation；反转的英文： reverse rotation。
例句：
Optimum Control of 35t/ h Boiler with Forward Moving Chain Grate Stoker by Computer Control System.
采用优化控制的35t／h正转链条炉微机控制系统。
情态动词用法
1、情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。
2、情态动词除ought 和have外，后面只能接不带to的不定式。
3、情态动词不随人称的变化而变化，即情态动词的第三人称单数不加-s。情态动词不受任何时态影响即不加三单。
4、情态动词没有非谓语形式，即没有不定式、分词等形式。
