At the beginning of each semester, Mr. Garza writes this on the board

"Speaking well and writing well are requirements for success."

Which punctuation mark belongs in the blank?

Answer: At the beginning of each semester, Mr. Garza writes this on the board:

"Speaking well and writing well are requirements for success."

Which punctuation mark belongs in the blank?

Explanation:

The colon is used to introduce long lists, extended examples or elaborations, or quoted material that can stand alone. This is an extended example of many things that Mr. Garza could write on the board, but this info in the quotes is very important. It can stand alone. He wants the students to know for sure that speaking well and writing well will win them success in his class.