How to prounce jqx and zcs correctly?

One of my student have trouble with distiguse PinYin jqx and zcs, is not only him as most of Chinese who from South part of China also has the same problem. Today, im gonna post two pic demonstrate the tongue postion of those sounds. Hope that will help you!

 the pic above is tongue postion j q x

this pic is tongue postion of z c s


Here is five tongue twisters to check if youve all done a good job with learning your PinYin!
https://www.youtube.com/watch?v=211vCE7rh38