Kathy ________ a lot of Spanish by playing with the native boys and girls.
They paid fifty percent of _____ they were able to earn to the state.
My sister is _______ about what she eats, otherwise she would not be so thin.
I know a little bit about the city as I __________ there for one year in my youth.
While working in the countryside, the students a great deal of knowledge on plant life.
Criticism and self-criticism _____ necessary _____ it helps us to correct mistakes.