Which of the following taxonomical aids is being described by the given statements (i-iv) ?
(i) They generally established in educational institutes.
(ii) They have collections of preserved plant and animal specimens for study and reference.
(iii) Insects are preserved in boxes after collecting, killing and pinning.
(iv) They often have collections of skeletons of animals too.

All the given descriptions are related to museum. Museum is one of the taxonomic aids which may be defined as a place where large collection of specimens of plants and animals are preserved for its further study and references. Museums are generally set up in educational institutes such as schools and colleges. Museums often have collections of skeletons of animals too. Specimens of plants and animals are preserved in the containers or jars in preservative solutions. These specimens may also be preserved as dry specimens.