You are right. I have difficulty to make correct"z"sound, even i know it should be easy to make as long as you hold your tongue in the correct position." singing" was wrong in the reading.I thought i had got th, long i and ai, it seems that i still need to do more work. Thank you very much for your suggestion. There is a long way for me to go.........
I really hope you could help me more by pointing out my mistakes. I mean, if you have time. Thanks again.