The sphincter closes after a bolus has been swallowed and enters the stomach. This sphincter is essential to prevent the contents of the stomach reentering the esophagus.

cramming before a final is bad because it makes a student's stress level higher. students who embrace cramming to get through a final exam week find themselves struggling to perform consistently, once the brain adjusts to prolonged sleep deprivation.

it's anything that aren't producers and consumers.

explanation:

you've got to be clear on what "this" is

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

glacial erosion, the picking up and movement of earth beneath a glacier, is also referred to as plucking. erosion and transportation of individual pieces of bedrock, especially large "joint block occur as a result of this glacial erosion. plucking is type of erosion in which rocks become frozen into the bottom and sides of the glacier.as the glacier moves downhill it 'plucks' the rocks frozen into the glacier from the ground.