my english teacher's voice sounds中sound为什么要加s

my english teacher's voice sounds中sound为什么要加s It's sounds great,为什么sound要加s? the song sounds very nice中,sound为什么加s? That sounds good.这里的sound为什么要加s? That sounds good的sound为什么要加s?直接sound不好了 That sounds boring.为什么sound加s啦 在这句Let us play volleyball,that sounds good中!为什么SOUND要加S呢?我要好 为什么Playing computer games sounds relaxing中的sound要加s? sound interesting 为何不加,That sounds good 为何要加s,如果用that sounds his voice sounds strange on the phone.sounds加s是因为his voice是单 The song sounds very interesting.sounds为什么要加s That sounds good中的sounds为什么要加s