Thanks a lot, 梅石莹玉. Your ID is as beautiful as your voice :).
Starting from now, I shifts my focus from sound to sentence stress and intonation. After practising my mouth around 50 days, my muscles move much smoother than before when pronouncing the sounds. I sort of have some feelings about the stress and intonation now but need to test them during my reading.
Lets good good study and day day up.