D. Things that are kept constant.
Controls are used in an experiment where some variable is being changed. By only changing one thing and keeping the others constant they can make sure that any change in the results is caused by the variable and not the constant, since the constant didn’t change.
Isn't this erosion?
i think it is...
The menstrual cycle is complex and controlled by many different glands and the hormones that these glands produce.
The four(4) phases of the menstrual cycle are:
(1) menstruation.
(2) the follicular phase.
(3) ovulation .
(4)the luteal phase.
Common menstrual problems include heavy or painful periods and premenstrual syndrome (PMS).
Answer:D) all of the above
Explanation:these are all correct because they all affect our environment
