Why length, mass and time are chosen as base quantities in mechanics?

If Planck's cosntant (h) and speed of light in vaccum (c ) are taken as two fundamental quantities, which one of the following can, in addition, be taken to express length, mass and time in terms of the three chosen fundamental quantities?

Using mass (M), length (L) time (T) and current (A) as fundamental quantities, the dimension of permeability is

If velocity of light c, Plank's constant h and gravitational ontant G are taken as fundamental quantities then express mass, length and time in terms of dimensions of these quantities.

Is force a scalar quantity? Why?

Why are sound waves called mechanical waves ?

Why are bases not touched or tasted?

Why does ammonia act as a Lewis base ?