Which phrase defines altitude? how tightly molecules are packed
a column of air pushing on an area
the force pushing on an area or a surface
the height of a given point above sea level

This is all you, but i can give you some topics that you could try. if it rained when you want to do something outdoors, it 'limits' that human activity. maybe you want to do an experiment that goes throughout the whole year and you have to have above freezing the entire year. this 'limits' your activity. i thought of those just off of the top of my head. something that gets to me that might be getting to you is you are thinking too hard about what to do. think simply, and if it is too simple, then bump it up just a little bit.

The correct answer should be brand c.

Answer feldspar,quartz,mica and amphibole;

Ok so i just did that quiz and here are the answers: 1. how is continental crust different from oceanic crust? a. continental crust is more dense and contains a lot of basalt.b.continental crust is thinner and younger. < c. oceanic crust is thinner and younger.d.oceanic crust is thicker and contains a lot of granite.2. where do subduction zones often occur? a.where a continental plate is being split into two partsb.where an oceanic plate is moving toward a continental plate < c.where two oceanic plates are moving away from each otherd.where two continental plates are colliding3. at which type of boundary do lithospheric plates collide? a.convection boundariesb.contour boundariesc.gravitational boundariesd.convergent boundaries < 4. what is the best description of a convergent boundary? a.plates that move side by side past each otherb.plates that are attracted to each other by gravity  c.plates that move away from each otherd.plates that move toward each other < 5. how can mountain formation be described according to the theory of plate tectonics? a.as two continental plates collide along a convergent boundary, mountains are formed. < b.as a continental plate and an oceanic plate come together at a divergent boundary, mountains are formed.c.as any two plates meet at a fault line boundary, mountains are formed.d. as two continental plates move past each other at a transform boundary, mountains are formed.