题目

We’d be very grateful if you could join us because your cooperation will________the timely completion of our project.        A．reach for  B．make for   C．go for       D．stand for 答案：B一只标有“6V 0.6A”的小灯泡，若加在其两端的电压是3V，则灯泡的额定功率是________mW，实际功率是________W．若把它接在电压为9V的电源两端并使它正常发光，则需要________联一个________Ω的电阻．