Among the selection criteria for the new polyurethane were that the material exhibited a combination of good wear characteristics and mechanical properties, was easy to handle, and provided for fast, easy alteration and repair of polyurethane as well as metal patterns.
A linguistic universal is a pattern that occurs systematically across natural languages, potentially true for all of them. For example, All languages have nouns and verbs, or If a language is spoken, it has consonants and vowels.
Interlanguage fossilization is a phenomenon of second language acquisition (SLA) in which second language learners develop and retain a linguistic system, or interlanguage, that is self-contained and different from both the learner's first language and the target language.