Un is masculine for example un stylo (a pencil).
Und is feminine, for example une table ( a table)
Answer:
The first statement is incorrect.
The second statement is correct.
Explanation:
1.C'est la troisième fois que je t'explique.
1.This is the third time that I explain to you.
Answer: it is supposed to be explained. With an "ed" at the end.
2. Cette petit fille est grand et gros.
2. This little girl is tall and fat.
Answer: this is a correct statement no wrong grammar.
The answer is C. Au revoir! À bientôt! This is because the sentence "à bientôt "means "see you soon." This is more suited to the occasion than "à plus tard", which means "see you later", and "à demain", which means "see you tomorrow", as well as just plain "au revoir", which means goodbye.