when i import mp4, the audio is slow

It might help if you actually read the online help on soem basics. Your preview frame rate is set to 22 FPS wheras the comp framerte is 30 FPS. The slowdown is therefore to be expected. Simply set the preview rate correctly.

Mylenium

Your video is only a single frame. There is no audio.

Are you waiting for the Ram Preview to render? Are you a new user? After Effects is not like an NLE. The duration of a ram preview depends on your system resources, and it must render before playing.