Because oxygen is circulated throughout the body via the bloodsteam, there is a strong connection between the cardiovascular system and the system. Group of answer choices
respiratory
digestive
endocrine
nervous

Because oxygen is circulated throughout the body via the bloodstream, there is a strong connection between the cardiovascular system and the respiratory system.

Explanation:

The cardiovascular system is responsible for the transport of oxygen to all tissues of the body, in addition to the removal of carbon dioxide, which depends on the close interaction with the respiratory system.

A summary of the strong connection between the cardiovascular and respiratory systems is :

Blood contains red blood cells, which are responsible for transporting O₂ and CO₂ by binding to the hemoglobin molecule, present in these structures. The respiratory system is responsible for providing air with O₂ and removing CO₂, a process that depends on gas exchange at the level of the pulmonary alveolus.

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.