(1) is a proposition that is true when x=2 or x=3, otherwise it is false.

(2) Not a proposition. The sentence "normal" can be understood as a question (but it must be understood as a rhetorical question, barely a proposition)

(3) It is a proposition, because it has been judged that the rectangle is a parallelogram and a true proposition.

(4) Personal prejudice is a proposition, which is true. China's language is too extensive and profound, like diplomatic language. If the teacher says yes, it is not. Remember the answer.