Ⅲ. Ellipsis after prep (Two prep share an object V作者现在从享于图像处理和识别的教学与研究 xxx The author is now engaged in the teaching and researching ofimage processing and recognition V必须求出这个电阻上的电流和电压 It is necessary to find out the current through and the voltage across this resistor V这位教把在研先和应用沃氏数( Walsh functions)方面 起了积极的作用Ⅲ . Ellipsis after prep. (Two prep. share an object) 作者现在从事于图像处理和识别的教学与研究 ※※ The author is now engaged in the teaching and researching of image processing and recognition. 必须求出这个电阻上的电流和电压 It is necessary to find out the current through and the voltage across this resistor 这位教授在研究和应用沃氏函数（Walsh Functions）方面 起了积极的作用