Answer:
The frogs circulatory and digestive systems are physically connected because the frog’s digestive system includes its liver and this has a hepatic portal system through which veins pass and come out and that is the circulatory system so they are connected.
Answer:The cardiovascular system consists of the heart, blood vessels, and blood. This system has three main functions: Transport of nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes (carbon dioxide, nitrogenous wastes).
Explanation:i hope that helped
Definitely decompose dead organisms, otherwise there would be no oil for us.