Answer:
cappillaries
they connect the arteries and the veins
<h2>540 million years ago
</h2>
Paleozoic.
Era immediately follows Precambrian It lasted about 4.5 billion years.
When did abundant fossil evidence first appear in the geologic record.
540 million years ago.
Answer:
Cation-exchange capacity is a measure of how many cations can be retained on soil particle surfaces. Negative charges on the surfaces of soil particles bind positively-charged atoms or molecules, but allow these to exchange with other positively charged particles in the surrounding soil water