【单选题】一载有电流 I 的细导线分别均匀密绕在半径为 R 和 r 的长直圆筒上形成两个螺线管,两螺线管单位长度上的匝数相等.设 R = 2 r ,则 两螺线管中的磁感强度大小 B R 和 B r 应满足: (A) B R = 2 B r . (B) B R = B r . (C) 2 B R = B r . (D) B R = 4 B r . [ ]
【简答题】The professor describes what happens during anaphylactic shock. Indicate whether each sentence below is a step in the process. For each sentence, click in the correct box.