Emotional health is evidenced in the voice by free and melodicsounds of thehappy，by constricted and harsh sound of the angry，and by dull and lethargicqualitiesof the depressed．
(evidence作动词——表现出来)
情感健康能够通过高兴者直爽、悦耳的声音，生气者急促、严厉的声音，和忧郁者沉闷、冷漠的声音而表现出来。
分句1：Emotional health is evidenced inthe voice
分句2：by free and melodic sounds of thehappy
分句3：by constricted and harsh sound ofthe angry
分句4：by dull and lethargic qualities ofthe depressed．
2，3，4并列
1和2，3，4嵌套
这个句子比较简单，重点是弄清楚evidence的歌词在这句话中意思，注意一词多义现象，要理解词的意思要注意联系上下文。
先登托福代报