<span>Acute exposure to radioactive substances.
Acute exposure is radiation exposure that occurs in a short time period. It can be an exposure that occurs once in your lifetime. This might be that one foot x ray you had because you may have broken your foot. Acute exposure can also be exposures that occur more than once, but very infrequently and for short periods of time. This might be dental x rays you get every few years.</span>
18: D, homologous
20: B, DNA
I can’t see 17 or 19!
Answer:
The food type changes in a given environment, then the amount of each type of bird beak will changes as birds with beaks more suited to the available food will consume more successfully over time. The independent variable of the lab is the type of food that is available to the birds.
