Hypothesis is what you think will happen before the experiment, it isn't necessarily backed up by any sources or evidence. A scientific law is the observation of a phenomenon and a theory is the explanation both can be used together to back each other up.
I believe it is B. Hope this helps!!
Vein because they have valves to prevent back flow of blood.
Plastics are made from non-renewable and non-biodegradable materials and are difficult to convert to environmentally friendly substances. As a result, the organisms and their habitat are facing danger that might lead to destruction, scarcity of food resources, and even death.
