When you change from the medium power objective to the high power objective, what
should you do?

You must have the object centered before you change objectives to increase the magnification, because the field of view becomes smaller; if the object is off to the side, it may disappear when you go to higher magnification. ... The higher the power of the objective lens, the less will be the depth of field.

Explanation:

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

can you attach the