Problems on Teclast T20 tablet

[slx]

I installed the scummvm from google play. I put the Zak McKracken FM-TOWNS version into the game list and it runs BUT there are 2 problems on Teclast T20 tablet.
1) the aspect ratio correction does not work and the game stretched horizontally;
2) the subtitle speed does not work either, it does not matter where I set it (ingame or in the options)!