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（）.

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

A.auditory
B.acoustic
C.articulatory
D.none of the above three

单项选择题In English, “pill” and “bill” are （）.

A.a phonemic contrast
B.complementary distribution
C.assimilation
D.a minimal pair

单项选择题As modern linguistics aims to describe and analyze the language people actually use, and not to lay down rules for correct linguistic behavior,it is said to be （）.

A.prescriptive
B.sociolinguistic
C.descriptive
D.psycholinguistic

名词解释什么是Duality; Duality名词解释定义是什么?

名词解释什么是acculturation; acculturation名词解释定义是什么?