An astronomical unit (AU) is the approximate distance from the earth to the sun. The answer is D.
Answer:
The correct answer is biological.
Explanation:
When any pathogen invades the body, it has to pass several lines of defence. The first barrier is the skin and mucous membrane which is a physical and chemical barrier. The second line of defence is the non-specific response by macrophages, neutrophils and interferon. After crossing these two barriers the third line of defence comes into action in which, the B- cells and T-cells act specifically on the pathogen and destroy it.
Those proteins are called apolipoprotien.
ANSWER ( Convergent plate boundaries )
At convergent plate boundaries, oceanic crust is often forced down into the mantle where it begins to melt. Magma rises into and through the other plate, solidifying into granite, the rock that makes up the continents. Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed.
B
(sorry I need more captions so....)
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