The only word that can be used before “chalk" is 

Questões de assuntos semelhantes

• Choose the correct alternative.
• As far as the teaching of standard English is concerned, the pluralization of the underlined noun is only acceptable in alternative:
• “...wives...” (line 2), have the same plural form as, except
• A suffix is a letter, or a group of letters attached to the end of a word to form a new word or to change the grammatical function (or part of...
• “thoughts”, (line 5), is