There are valves in the vessels that prevents backflow, just like in the viens. ... the lymph vessels to ensure that the flow of lymph
correct answer is d. all plants and animals in grand canyon
I positive that the answer id D why because Without<span> them the Earth </span>would<span> be too cold for us, or any other living thing, to survive. Naturally occurring </span>greenhouse gases<span>, such as carbon dioxide and methane, allow solar radiation to reach the Earth's surface, while trapping radiation from the Earth on its way back out to space.
Hope I helped
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