Answer:
If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano. ... If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode.
Explanation:
An archipelago...........
<u>Answer:</u>
<em>Anytime observations need to be clarified. When an unusual condition need to be shown for later reference.</em>
<u>Explanation:</u>
Instead of just recording the data the is sometimes important to be sketched out as the data observed is needed to be clarified and also sometimes there is an unusual condition that occurs and hence, it is important to sketch it so that it can be used for later reference.
<em>Therefore, when we are aware of the situation we need not sketch the data.</em>
