Varieties of a language are of four types: the standard variety, regional dialets, so

Software products may be (1)into four basic types: application programs, programming language processors, operating systems, and system utilities.

Application programs are programs that (2) useful tasks such as solving statistical problems, or keeping your company's books.

Programming language processors are programs that (3) the use if a computer language in a computer system. They are tools for the development of application programs.

Operation systems are programs that (4) the system resources and enable you to run application programs.

System utilities are special programs that (5) the usefulness of or add capabilities to a computer.

A．manage

B．perform

C．support

D．reduce

E．divided

American English and British English are social varieties of the English language. ()

A.varieties

B.tops

C.respects

D.ecks

____ refers to varieties of language defined by their topic and context of use.

A. stress

B. tone

C. register

D. intonation

Can you tell the difference between() mushrooms and edible(可食用) varieties？

A poisonous

B attractive

C endless

D functional