题目

Mrs. King has __________ China for over 3 years. A. gone to               B. been to                    C. come to            D. been in 答案：D一只耐压值为10V的电容器，如果把它接在交流电路中，则   [     ]A、交流电压不得超过5V       B、交流电压不得超过V  C、交流电压不得超过10V     D、交流电压不得超过V