We all know that learning a foreign language _______ time and effort.
This year the Christmas party of our school is _______ 18:00 _______ Monday evening.
Linda eats ________ rich food. She must change her diet.
Amy thinks hamburgers are not healthy, so she _________ eats them.
It takes Jack ______ hour to practice playing _______ volleyball every day.
Li Ming plays the piano ___ a hobby.