A microphone enables a soft tone to be amplified, thus making it possible the gentle rendi

听力原文：（A) A man is singing into the microphone.（B) A man is touching the strings.（C) A

（47）__________ 查看材料A.wireless microphone is attache

（48）__________ 查看材料A.wireless microphone is attache

（49）__________ 查看材料A.wireless microphone is attache

（50）__________ 查看材料A.wireless microphone is attache

English is a typical tone language.（)