D. Coal is naturally made and cannot be renewed by humans.
Answer:
The Quantum Model of the Atom 1927
Explanation:
It is the most accurate model of the atom but I don't know about the easiest to visualise. Soz :(
Lamprey and hagfish are jawless fish, with skeletons composed of cartilage. They do not have scales and are considered primitive fish. They are in the superclass cyclosystoma.
Answer:
The correct option is Blood cells are produced in bone marrow.
Explanation:
Skeletal system can be described as the system which comprises of all the bones and joints of an organism. The main function of the skeleton system is to provide support and protection to the organism.
The circulatory system can be described as a system which comprises of the heart, blood vessels and blood. This system is mainly involved in the transportation of substances like oxygen, nutrients etc in the body.
The skeletal system interacts with many other systems of the body and helps them perform their functions. For example, the skeletal system interacts with the muscular system so that a muscle can contract and relax.
The skeletal system interacts with the circulatory system by producing blood cells in the bone marrow. Red blood cells, as well as white blood cells, are produced by this process.
D. secondary
Two groups: primary and secondary
The primary groups has stronger and deeper relationships with its member/s than secondary groups, many of which are superficial gatherings and surface dealings.
Primary groups include:
1. Family
2. Lover
<span>3. Husband/Wife </span>
Secondary groups:
1. Colleagues
2. Classmates
3. Friends
<span>4. Acquaintance</span>