B. The ability to respond to the environment good decision
In geology, a graded bed is one characterized by a systematic change in grain or clast size from one side of the bed to the other. Most commonly this takes the form of normal grading, with coarser sediments at the base, which grade upward into progressively finer onesI just learned about this in our rocks and minerals unit for science,
Answer:
of the low pH of the vagina.
Explanation:
The pH of the vagina is maintained at highly acidic levels to prevent the germ buildup. The range of vaginal pH is around 3.8 to 4.5. The very low pH of the vagina creates a hostile environment for sperms and most of the sperms are killed as they enter the vagina due to the acidic pH.
Apart from supplementing the sperms with energy, cervical mucus serves to protect the sperms from the hostile conditions of the vagina. The cervical mucus has an alkaline pH at or near the ovulation to protect sperms from acidic pH of the vagina and to facilitate fertilization.