A covalent bond is a chemical bond which involves the sharing of atoms.
The correct answer is B.
The humans forearm is much like a bat wing, because all of our tendons and liniments. Although we do not use the structures in the same ways, they are alike.
<span>Yes,
there are mammals that lay eggs instead of giving birth to a live young. These mammals
are called Monotremes. One best example to this is the platypus and echidnas.
Platypus, which is also known as the duck-billed platypus, is a semiaquatic
egg laying mammal. Echidnas on the other hand are also called as spiny eaters.
Echidna and platypus are only the surviving members of the Tachyglosside. And are
the sole extant egg laying mammal</span>
The right answer is: vitamin C and choline
Choline (vitamin B4) is the precursor on the one hand acetylcholine (important neurotransmitter and neuromodulator) and on the other hand, the cascade initiated by betaine (intermediate in the biological methylation and precursor of membrane lipids). In this, it is considered, by extension, as an integral part of the family of B vitamins,
Vitamin C protects against cellular aging, is essential for the immune defenses and increases the assimilation of iron of plant origin. It also contributes to the formation of collagen. Its deficiency leads to a disease called scurvy (hence the ascorbic acid name of vitamin C).
The two substances are rock (molten and solid) and metal (solid + liquid).
Layers of the earth from the outside in:
1. crust. hard rock/dirt/ground. Shell
2. mantle. melted rock and stuff. Egg white
3. core. Outer core - liquid. Inner core- solid. Nickle and iron. Yolk
