题目

World Tai Chi and Qigong Day is an event held on the last Saturday of April each year，which promotes(倡导) practices of Tai Chi and Qigong.Followers of Tai Chi and Qigong especially hope to educate the world about the health benefits(益处) of the two exercises.The World Tai Chi Day website says it is also a day to help put people in touch with teachers and healing(治疗) centres.This event，which started in 1999，joins people in over 65 countries.That number grows every year as Tai Chi becomes better known.Celebrations include Tai Chi exhibitions(表演) in many cities around t为判断一段导线中是否有直流电流通过，手边若有下列几组器材，其中最为方便可用的是（ ）A．小灯泡及导线B．铁棒及细棉线C．带电的小纸球及细棉线D．被磁化的缝衣针及细棉线