The noun "lobo" means "wolf," what is the word for female wolf, she-wolf?

Based on its ending, the Spanish noun "píldora" , pill, is most likely to be ...

Based on its ending, the Spanish noun "ansiedad", anxiety,  is most likely to be ...

In Spanish, the plural of "papel" (paper) is...   

In Spanish, the plural of "vez" (time, like in three times) is...