The instructions say “Complétez avec les adjectifs démonstratifs (ce/cet/cette/ces)”, which means “Complete with the demonstrative adjectives (this/that/these/those)”.
In French, the choice of demonstrative adjective depends on the gender (masculine/feminine), number (singular/plural), and the first letter of the noun it precedes. Here’s a quick guide:
Use “ce” before a singular masculine noun that begins with a consonant. For example, “ce livre” (this book).
Use “cet” before a singular masculine noun that begins with a vowel or silent ‘h’. For example, “cet homme” (this man).
Use “cette” before a singular feminine noun (regardless of whether it starts with a vowel or consonant). For example, “cette femme” (this woman).
Use “ces” before all plural nouns, regardless of gender. For example, “ces livres” (these books).
I hope this helps!