题目

 . Because her family is too poor, she has to ____ on her uncle for further education in the university.      A. keep                       B. feed            C. have                         D. Depend 答案：D5．如图所示，根据小磁针的指向，对电磁铁的南、北极和电源的正、负极判断正确的是（　　）A．a端是北极，c端是负极B．a端是北极，c端是正极C．a端是南极，c端是负极D．a端是南极，c端是正极