两平行直导线相距为d,每根导线载有电流I1=I2=I,且电流方向相同,则两导线所在平面内与该两导线等距离的一点处的磁感应强度为。
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Task 2 Choose the best answer for each of the following sentences.1. The placeinterested me most was the Children's Palace.
A. which
B. where
C. what
D. in which
修改后的我国《婚姻法》在结婚制度方面确立了()和()制度。