In one sentence, describe what the following article is about: Hay forms the foundation of a rabbit's diet. Not only is this important for nutrients, but fiber as well. Since rabbits clean themselves, they often swallow a lot of hair. Without adequate fiber, these hairballs can block the GI tract and can be fatal. Chewing hay also keeps the rabbit's teeth at a healthy length by wearing them down and preventing them from overgrowing.  Feed your rabbit grass-based hays like timothy, oat, or wheat. Other hays like alfalfa may be too rich in calcium or protein for your rabbit to handle. To choose a good quality hay, look for a tinge of green and a sweet smell. Poor quality hay is completely yellow and may smell musty. Do not feed your rabbit a poor quality hay.  If you cannot find a good hay at a local pet store, there are mail order companies that can ship you the right hay.  Rabbits can be fed hay from birth. Like with most animals, water is essential for health and well-being. Without adequate water, a rabbit can become dehydrated, go into organ failure, and die. Your rabbit should have fresh drinking water at all times.  A water bottle or ceramic/stainless steel bowl is sufficient to give your rabbit water. Keep in mind that your rabbit may drink more from a bowl than a bottle, which is good for the rabbit's health. You can start with both to see what your rabbit prefers. Whatever method of providing water you choose, be sure to use lead-free products. Replace old water with clean water every day. Also be sure to clean water bottles and bowls with hot water and soap daily to prevent bacteria growth. Rinse these thoroughly to make sure all soap residue is washed away. The best vegetables for your rabbit are romaine lettuce, broccoli, carrots, cilantro, spinach, and celery.  Make sure any vegetables you feed to your rabbit are fresh. Vegetables even a few days old can make your rabbit sick. Serve vegetables wet to increase your rabbit's fluid intake and help the food flow more easily through the GI tract. Switch up the vegetables you give your rabbit every day. Some rabbits, when fed only one type of vegetable, can develop sludge in the bladder which may then form into bladder stones. A typical example is carrots which are high in oxalate. Feeding carrots every day can predispose a rabbit to bladder problems. To avoid this, never give the same food two days in a row. If your rabbit eats carrot one day, offer broccoli next so you're constantly mixing things up. Fruits should be considered a treat and should not form the base of your rabbit's diet. Generally you should limit fruit servings to no more than two tablespoons per day.  All fruits are considered safe for feeding to rabbits, as long as they are in controlled quantities. Mix up your rabbit's fruit intake daily, the same as you would with vegetables. Commercial rabbit pellets are generally not considered essential for a rabbit's diet- they don't provide the fiber or the tooth exercise that hay provides. They are also high in calories and can cause obesity if your rabbit eats too much of them. In limited quantities, however, pellets can provide vitamins and minerals that your rabbit needs.  Remember that pellets should only be a supplement to other foods, and not form the foundation of your rabbit's diet. Pick pellets that are timothy-based rather than alfalfa-based. Alfalfa pellets tend to be higher in calories and can cause obesity. Pellets come in two forms: muesli and extruded. Muesli types have individual nutrients in each pellet, while extruded types have all nutrients mixed into each pellet. Use extruded types to give your rabbit all the essential nutrients he requires. With muesli types, your rabbit may pick out tasty pellets and neglect others, leading to deficiencies.  Talk to your vet for the ideal portion size for your rabbit. Some recommended servings for adult rabbits are as low as 1 tablespoon (14.8 ml) daily.  If your rabbit starts neglecting his hay, cut back on pellets. A lack of fiber from hay can cause a fatal blockage in your rabbit's GI tract, so you'll want to make sure it is the primary food in the rabbit's diet. Rabbits have sensitive digestive systems and you shouldn't feed them anything unfamiliar. Specifically avoid nuts, seeds, corn, or any dessert foods like chocolate. Your rabbit won't be able to digest these foods and consumption of these could be fatal.  Also avoid any gourmet rabbit treats. These can be harmful. Always check with your vet before feeding something new to your rabbit.
Summary: Give your rabbit unlimited quantities of hay. Provide your rabbit with plenty of water. Add fresh vegetables to your rabbit's diet. Feed your rabbit fruit as a treat. Provide rabbit pellets in limited quantities. Avoid feeding rabbits anything not included on this list.

In one sentence, describe what the following article is about: However skilled a very young musician may be, they are not the ideal candidate to buy a cello for. Young children are known for going through very rapid growth spurts: as elementary school students, they'll grow about 2½ inches in just a single year. Part of what determines the cello you should buy is your size, and fractional size instruments are notoriously difficult to resale. To avoid having to buy a brand new cello again within six months or a year, consider renting a cello instead for those who need anything up to a ¾ size. Are you brand new to playing the cello? Are you sure you plan to continue playing the instrument in the years to come? Will playing the cello be a hobby for you, or do you have plans to pursue it professionally, or even semi-professionally? If you aren't sure if you will continue to play the cello for many years and do not intend to take it at least semi-professionally, then you may be better off renting a cello until you're sure. Cellos are extremely expensive: for a good fractional, teachers advise students spend no less than $700; a good, full-sized cello for an adult will be at least $2000. Anything less expensive than that is not a good instrument and should be avoided. If you cannot afford to spend that much on buying a cello, renting is the better alternative.
Summary:
Consider renting for small children. Consider your skill level. Consider your budget.