【单选题】.My twin sister is ______ me. Art is my favorite, but she doesn’t like it.
【单选题】My sister wrote me to make _____.
【单选题】He didn't notice me in the crowd but he spotted my sister who was _______ because of her red hair.
【单选题】My roommate wrote that letter ______ me. I couldn't do it because I sprained my wrist while playing volleyball.
【单选题】-Haven’t you heard from your sister? -____________ She wrote a letter to me last week.
【简答题】空气中的电场强度 V/m ,则位移电流密度 = 。
【简答题】空气中的电场强度 V/m ,则位移电流密度Jd = 。
【简答题】弧菌科细菌和肠杆菌科细菌鉴别主要依靠——试验
【单选题】下列关于灯丝变压器的说法,错误的是
C.
初级线圈工作电流较大,所用的导线比次级线圈直径粗
D.
灯丝加热变压器指的是给 X 线管提供灯丝加热电压的变压器