17. Few people know about the complex science behind the construction of elevators. (1 point)

demonstrative adjective
interrogative adjective
indefinite adjective
proper adjective

Which word are you supposed to identify? What do you think it is?

The correct answer is "proper adjective." A proper adjective is a word derived from a proper noun, such as a place, person, or organization, and is used to describe something related to that noun. In this sentence, "complex" is derived from the noun "science" and is used to describe the kind of science behind elevator construction. It is a proper adjective because it is specifically related to the science of elevator construction.

The word "complex" in the sentence is an indefinite adjective.