If there is a possibility of four different genotypes in the offspring that result from a dominant-recessive inheritance, and if the couple has four children, would they definitely have children with one expressing each genotype?

yes

Explanation:

they would have one expressing each genotype either in the first cross or second or third

d. the weight of the book

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.