Crayfish are invertebrates which means they don't have a backbone. They are also arthropods, which means that they have a protective exoskeleton on the outside of their body. Other arthropods include insects, spiders, and centipedes. Crayfish continually shed their exoskeleton and regrow a new one. During this transition is when they are most vulnerable to predators because they aren't protected by their outer shell.
Crayfish are found all over the world in many different freshwater environments, such as rivers, creeks, springs, and swamps. But this doesn't necessarily mean that you will be able to find them. They are somewhat cryptic because they dig out homes for themselves under rocks and blend in well with their environment. Crayfish will ardently defend this dwelling against intruders using their strong front claws
The right answer is Electromagnetic waves can transfer energy through empty space.
Electromagnetic radiation refers to a form of linear energy transfer. Visible light is electromagnetic radiation, but is only a small slice of the broad electromagnetic spectrum. The propagation of this radiation does not need material to move.
if we take the example of solar energy, it spreads in space, the atmosphere until reaching the earth.
Once it reaches a material, it gives rise to many phenomena such as attenuation, absorption, diffraction and refraction, redshift, interferences, echoes, electromagnetic parasites and biological effects.
B. It was an explanation for how the earth originated.
The answer is base pairs.