Yes it can, depending on the nature of the excerpt and how it is used. The four factors that have to be considered before "fair use" can be established are...
the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
the nature of the copyrighted work;
the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
the effect of the use upon the potential market for or value of the copyrighted work.
no as long as you site the source, like a bibliography