2 按照观察所发生的地点来划分，观察可分为（ ）

单项选择题渴望被别人信任、承认和重视，是少年儿童最大的心理需求。（ ） A、正确 B、错误

单项选择题Which one of the following four statements is true? A、An induced electric field is caused by a stable magnetic field. B、An induced electric field is caused by the motion of charges. C、A displacement current is the rate of change of charges. D、A displacement current is caused by a time-varying electric field.