Astudent placed a stack of rocks on a ramp. she added clumps of soil rooted
with live grass. using a garden hose, she then applied a steady spray of water
that soaked into the soil, making it heavier. what does the student's
experiment model?

The student's experiment is modeled after mass wasting, which is also known as mass movement or slope movement. One of the factors of mass wasting is gravity. The water from the hose weighs down the soil and causes the clumps of soil to move downward through the stack of rocks.

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.