st, sk, sp When stressed, st, sk, and sp undergo sound changes; At the beginning of words, st, sk, and sp change their sound, but at the end of words,[......] 继续阅读
st, sk, sp When stressed, st, sk, and sp undergo sound changes; At the beginning of words, st, sk, and sp change their sound, but at the end of words,[......] 继续阅读