She further explains musical training and learning to speak each make us think about what we are doing2. She says speech and music pass through a structure of the nervous system called the brain stem. 3 . Until recently, experts have thought the brain stem could not be developed or changed. But Professor Kranss and her team found that musical training can improve a person's brain stem activity.
The study involved individuals with different levels of musical ability. They were asked to wear an electrical device that measures brain activity. The Individuals wore the electrode while they watched a video of someone speaking and a person playing a musical instrument -- the cello. 4 . The study found that the more years of training people had, the more sensitive they were to the sound and rhythm of the music3. Those who were involved in musical activities were the same people in whom the improvement of sensory events was the strongest. 5 She says using music to improve listening skills could mean they hear sentences and understand facial expressions better.
词汇：
retardation n. 滞后 cello n. 大提琴
note n. 音符 rhythm n. 节奏
electrode n. 电极 sensory adj. 知觉的，感官的
注释：
1.scientists believe that could help children with learning disabilities：科学家发现，音乐训练、对学习上有障碍的儿童有帮助。that是从句“that could help children with learning disabilities”中的主语。that指代上一句的developing musical skills involves the same process in the brain as learning how to speak。with learning disabilities是定语，修饰children。
2.musical training and learning to speak each make US think about what we are doin9：音乐训练和学习说话这两者都使我们思考我们正在所做的事。each指musical trainin9和learning to speak中的任何一个。句子的主语是musical training and learning to speak，所以，谓语动词是复数的。
3.the more years of training people had，the more sensitive they were to the sound and rhythm of the music：人们接受音乐训练的年份越长，其对音乐声音和节奏的敏感性也越高。people是前半旬中的主语。
练习：
A Both involve
