What kind of speaker is better for teaching?

Little Dolphin's streamlined speaker series, with national patent design, sound quality and workmanship, is currently the leader in the domestic speaker industry and series products. Lithium battery digital speaker series. On Baidu, Zhengzhou Yin Qi Electronics has detailed contact information. The address is 2C22, Bainaohui, Dongfeng Road, Zhengzhou, which is the factory office in Henan.