It is pronoumced by raising the tongue tip against the upper teethridge to block the air and then putting it down to release the air.

下唇和上，形成一条狭缝，气流狭缝中磨擦而出。

It is pronounced by raising the tongue tip against the upper teethridge to block the air and then putting it down to release the air.

舌上龈，阴气流，然后移下舌，放出气流。