Answer: 1. Dwarf Star 2. Helium to Carbon 3. Xray
Explanation: I just took the test. Trust me!!!
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
Answer:
The concentration gradient of oxygen in your lungs wants to flow toward homeostasis and oxygen is bound on red blood cells by hemoglobin, along with the attraction of oxygen to hemoglobin. The concentration gradient from carbon dioxide from the capillary to the lungs. There is more oxygen in your lungs (alveoli) than there is carbon dioxide and everything want to reach homeostasis, or level amounts on both sides.
Explanation: