Things such as coal and oil are limited because they are only found in some places
The correct answer is that mammals use a closed, double loop , four chambered heart as a circulatory system of the body.
The circulatory system of mammals is closed system that consists of four chambers, two articles and two ventricles. The deoxygenated blood comes into the heart from one loop and the oxygenated blood from other loop from the heart is circulated to the whole body. This is called as double circulation.
I believe the answer to 11 is that multicellular organisms are made up of multiple cells and unicellular organisms are made up of one cell.
Supongo que solo trata de probar cuál es cuál con una prueba que inventas. eso es muy confuso
Because technically there is no such thing as cold
all that exists is heat
this is because heat is the rapid movement of particles, made by friction (to understand why you must delve into physics and some chemistry)
so, when you feel cold, it's really the absence of heat
so instead of "keeping the cold out", which makes no sense at all scientifically, insulation keeps the heat in.
as a side note
the feeling of cold is produced when you come in contact with an object (yes, air counts) that has less heat, or energy, than you do, You feel cold because heat (energy) from your body is being transferred to the environment. This ABSENCE OF HEAT in your body is why you feel cold
