What Are The Two Main Forces Acting On A Plane At Taking Off?

I see this Is your homework Grampa!!!!
Oops, I'll probably get another bad rating for this one.
 Are you going to aeronautical school, Grandpa?
Aren't you going to retire soon?
Anyway, I think you are right. Thrust and lift.

I would guess gravity and lift.
 
I'm sure someone will let me know if I am wrong.

Why only two?
There are four significant forces acting on a plane at take off (and flight):

1. Thrust


2. Friction (drag)


3. Gravity


4. Lift (dependant on velocity of air over the airfoil).

 

That's right grandpa, thrust and lift are the things that make a plane fly!

Thrust and lift

The two main forces are push and pull