Final answer:
The synonym for 'demonstrate' is 'display' and the antonym for 'conceal' is 'hide', making option A ('Display, Hide') the correct answer. Additionally, the letter 'b' is underlined in the provided words to demonstrate the understanding of letter placement within each word.
Step-by-step explanation:
The question at hand is asking to match synonyms and antonyms to the given words. The word demonstrate has a synonym 'display', which means to show or exhibit something.
Similarly, the word conceal means to hide something; therefore, the antonym would be 'hide'.
Consequently, option A ('Display, Hide') is the correct matching pair for these synonyms and antonyms.
To underline the letters that spell 'b' in each of the given words, the correct parts of the words would be underlined as follows: able, scrible, resemble, pebble, tremble, noble, gamble, and bubble.