When my bathtub or my kitchen sink drain my toilet also drains out all the water in the bowl. What do I do?

When my bathtub or my kitchen sink drain my toilet also drains out all the water in the bowl. What do I do?
I can answer that in one word, "SUCTION".
You have a blocked vent or vents that's causing your fixtures to attempt to vent through the toilet and the suction is what's pulling the water out of your toilet bowl.
The solution would be to snake both the lavatory and kitchen roof vents.
In each case put out enough snake to reach the base and 20 feet more. Good luck, Tom

Thanks Tom, I will give it try.