Of the three branches of phonetics, the longest established, and until recently the most highly developed, is（）phonetics.

What essentially distinguishes semantics and pragmatics is whether in the study of meaning （）is considered.

registers

The compound word "bookstore" is the place where books are sold. This indicates that the meaning of a compound is the sum total of the meanings of its components.

What the element ‘-es’ indicates is third person singular, present tense, the element ‘-ed’ past tense, and ‘-ing’ progressive aspect. Since they are the smallest unit of language and meaningful, they are also（）.