【单选题】What did you do last Sunday? [ ]
【单选题】---I like hiking. What about you? ---So I.
【简答题】如图7-18(a),在竖直平面内有两光滑固定细棒,分别与竖直轴夹角30°,两棒上各串有一带电小球,可自由滑动。已知两小球各带电 ,质量都为m=1.10g,试求两小球的平衡位置及所受棒的支持力。
【单选题】—______ do you like the film, American Captain 3? —It’s wonderful! I like it very much.
【简答题】单相桥式整流电路电阻性负载时,对单相桥式全控整流电路与半控整流电路可做如下比较:控制角的范围相等,均为 ( )