What river forms a natural barrier between the United States and Mexico?

hi there!

question - how does mountainous terrain affect settlements in a region? choose all answers that are correct.

groups trade with each other regularly.

people travel from settlement to settlement.

why: since they travel to go trade or visit it may be harder to get there because of the mountainous terrain.

hope this : )

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.

answerinternational border(ib);