When a spider weaves a web, this is an innate, or instinctual action. A spider needs no training from other spiders (including its parents) to know how to spin a web.
I wanna say D, but I’m not entirely sure
So the the main forces that keep the water on the surface of the planet are to do with plate tectonics. If the plates were to stop moving, the water probably would eventually be absorbed into the interior, although this process would take a very long time indeed.
Scientists
can also glimpse the awful effects of Alzheimer's disease when they look at
brain tissue beneath the microscope:
Alzheimer's tissue has numerous fewer nerve
cells and synapses than a well brain.
<span>
<span>Plaques, unusual
clusters of protein particle, which are construct up between nerve cells.</span>
</span>
<span>
<span><span>Dead and dying nerve cells contain tangles,</span> which
are produce of twisted strands of a further protein.</span>
</span>
<span>Scientists
are not absolutely sure what causes cell death and tissue deficiency in the
Alzheimer's brain, but plaques and tangles are key suspects.</span>