Write the following articles and nouns in their plural forms:

el lápiz
la nariz
el profesor
el ratón

los lápices

las narices
los profesores
los ratones

los lápices

las narices
los profesores
los ratones

To form the plural of the given articles and nouns, we'll follow the standard rules of pluralization in Spanish.

1. el lápiz -> los lápices
To make "el lápiz" plural:
- Remove the singular article "el" and replace it with the plural article "los."
- Then, add the plural ending "es" to the noun "lápiz."

2. la nariz -> las narices
For "la nariz" in plural:
- Replace the singular article "la" with the plural article "las."
- Add the plural ending "es" to the noun "nariz."

3. el profesor -> los profesores
In the case of "el profesor" plural:
- Replace "el" with "los," the plural form of the article.
- Since "profesor" ends in "-or," we simply add the plural ending "es" to make it plural.

4. el ratón -> los ratones
For "el ratón" in plural:
- Change the singular article "el" to the plural article "los."
- Add the plural ending "es" to the noun "ratón."

So, the plural forms of the given articles and nouns are:
- el lápiz -> los lápices
- la nariz -> las narices
- el profesor -> los profesores
- el ratón -> los ratones