Nouns may have other modifiers besides adjectives. Stage-level predicates allow modification by manner adverbs and other adverbial modifiers. Variables without modifiers are not randomized. Nouns precede their modifiers, such as adjectives and possessors. These additives may consist of stabilizers, impact modifiers, pigments and lubricants. The dependents may be objects, complements, and modifiers (adverbs or adverbial phrases). For adjectival, adverbial, nominal modifiers, linkers are prohibited in predicate position. Friction modifiers and extreme pressure additives shall not be used. Chinese relative clauses, like other noun modifiers, precede the noun they modify. For more information about possible modifiers and dependents of nouns, see Components of noun phrases. The punctuation of compound modifiers in English depends on their grammatical role. Demonstratives, numerals, and possessive pronouns come after the head like other modifiers. Pyruvate kinase activity is most broadly regulated by allosteric effectors, covalent modifiers and hormonal control. Like many human diseases, environmental effects and genetic modifiers result in incomplete penetrance. It is made from asphalt and a variety of rubber modifiers and solvents.