If the comet has enough movement energy, it might leave the Solar System forever. Otherwise, the Sun's gravity will eventually slow it down, and the comet will return.
Comets are often thought of as visitors from other solar systems. Solitary travelers in space. Asteroids can and do exist as "belts" and are usually found in groups that can orbit a central sun very much like planets. Composition can be very different for both objects. Both follow prescribed orbits, hence we are able to predict/know the returning date for Haley's Comet. Am not familiar with any data about asteroids with orbits as far reaching as comets. Because comets follow a predicted orbit, and visit our solar system at regular times, they could be considered part of our solar system the same way as band of asteroids. However, comets can and do leave our solar system and pass through others, so they are more visitor than permanent part of our solar system.
Yes. The solar system is everything that orbits the sun.
Most "asteroids" are in orbit around the Sun, unless disturbed by gravity or collisions. Comets may orbit the Sun regularly, or be drawn in from the outer solar system and pass by the Sun on their way back out (hyperbolic comets).
Yes, you can leave your car at Hertz when returning it after your rental period.
By definition, long period comets come from within the gravitational pull of this solar system; when they leave the solar system, they are no longer considered to have a period.
Yes and no. On one definition it has. However, on another definition it has not and it will not for thousands of years. That definition is the outer edge of the Oort cloud of comets.
I don't know either (:
No. Any impurities in your body can or will leave your body through your urine or feces. By returning your urine into your body your are returning the impurities back into yourself. Thus your are re-contaminating your body. To properly cleanse yourself, I suggest drinking water.
It is not required to vacuum your rental car before returning it, but it is a good practice to leave it clean and tidy.
Veins return, Arteries leave the heart.
It is the trails they make. With comets it is the trail made by outgassing as the comet approaches and recedes from the sun. Meteors are heated by friction when they enter the atmosphere and leave a trail this way.
The dust and rocks that come off the comet often catch on fire and leave a trail.