Due to their low cost, ease of manufacture, versatility, and imperviousness to water, plastics are used in a multitude of products of different scale, including paper clips and spacecraft. They have prevailed over traditional materials, such as wood, stone, horn and bone, leather, metal, glass, and ceramic, in some products previously left to natural materials.
In developed economies, about a third of plastic is used in packaging and roughly the same in buildings in applications such as piping, plumbing or vinyl siding Other uses include automobiles (up to 20% plastic, furniture, and toys  In the developing world, the applications of plastic may differ—42% of India's consumption is used in packaging

Plastics have many uses in the medical field as well, with the introduction of polymer implants and other medical devices derived at least partially from plastic. The field of plastic surgery is not named for use of plastic materials, but rather the meaning of the word plasticity, with regard to the reshaping of flesh.

The world's first fully synthetic plastic was bakelite, invented in New York in 1907, by Leo Baekelan  who coined the term 'plastics' Many chemists have contributed to the materials science of plastics, including Nobel laureate Hermann Staudinger who has been called "the father of polymer chemistry" and Herman Mark, known as "the father of polymer physics"

The success and dominance of plastics starting in the early 20th century led to environmental concerns regarding its slow decomposition rate after being discarded as trash due to its composition of large molecules. Toward the end of the century, one approach to this problem was met with wide efforts toward recycling.

Multiple choice items consist of a stem and several alternative answers, among which are the correct ("keyed") answer and one or more incorrect ("distractor") answers. The stem is the beginning part of the item that presents the item as a problem to be solved, a question asked of the respondent, or an incomplete statement to be completed, as well as any other relevant information. The options are the possible answers that the examinee can choose from, with the correct answer called the key and the incorrect answers called distractors.[4] Only one answer can be keyed as correct. This contrasts with multiple response items in which more than one answer may be keyed as correct.
Usually, a correct answer earns a set number of points toward the total mark, and an incorrect answer earns nothing. However, tests may also award partial credit for unanswered questions or penalize students for incorrect answers, to discourage guessing. For example, the SAT Subject tests remove a quarter point from the test taker's score for an incorrect answer.