B. Subgroups
<span>When constructing a dichotomous key, the first step is to look at the group of objects or organisms and separate them into two groups based on a single distinguishing characteristic. Then continue to separate each of the groups until each object has its own separate set of characteristics.</span>
Fossil records indicate that eukaryotes evolved from prokaryotes somewhere between 1.5 to 2 billion years ago
Answer:
Flouride treatment
Explanation:
Dental caries refer to a tooth decay that lead to permanent holes in the teeth. It is more controlled by flouride treatment because flouride is a powerful mineral Fluoride help to make teeth develop resistant acid attacks contain in sugars and also bacteria thereby preventing tooth decay and also reverses it.