Smoking marijuana can be unhealthy as smoking cigarettes and

Medical marijuana is much healthier than cigarettes. Street weed is worse though. Marijuana is used on cancer patients to help reduce the spread of cancer through the body. I'm not sure if it helps with lung cancer, but I would assume not. Trust me, I have smoked for a couple of years, and it hasn't given me any bad effects.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

just did the assignment and the answer was #1 +2 n