that sounds good 这里sound为啥加s

that sounds good 这里sound为啥加s That sounds good.这里的sound为什么要加s? sound interesting 为何不加,That sounds good 为何要加s,如果用that sounds That sounds great.sounds 为啥加s. That sounds good的sound为什么要加s?直接sound不好了 That [ ] a good idea .A sounds B sounds like C sound 说明为啥. That sound good 还是That sounds good That sounds boring.为什么sound加s啦 That sounds good中的sounds为什么要加s 在这句Let us play volleyball,that sounds good中!为什么SOUND要加S呢?我要好 Those sound interesting.That sounds good. That book sound good 还是That book sounds good