题目

如图所示，A、B、C、D是匀强电场中一正方形的四个顶点，已知A、B、C三点的电势分别为φA=15 V，φB=3 V，φC=-3 V.由此可得D点电势φD=_________V. 答案：9Jack asked me ________ yesterday afternoon.A. when I go to the party B. when do I go to the partyC. why I didn’t go to the party D. why did I go to the party