Which of the following is a method used to prevent soil erosion? a. tilling the soil / b. contour farming / c. adding worms to soil / d. adding fertilizers to soil

B. Contour farming

Explanation:

Contour farming is a sustainable practice of conserving the soil from erosion so as to retain it's fertility for the next harvest.  In this method plants are grown over the contours of the slopes at a slight elevation. This process allows the absorption of water by the soil and prevents the surface runoff. Hence, prevents the loss of soil fertility by soil erosion due to water.

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)