-- _____is that used for?---_____ the floor.
—What clothes should we wear to attend the ball?—Dress ________ you like.
How many nationalities ______ our country ______?
—The 3D cinema provides a brand new experience of ________ space.—Yes. You can even take ________ journey to the end of the solar system.
I have had such a case __________a boy whispered to his classmate now and then while I was having lessons.
So difficult __________ it to work out the problem that I decided to ask Tom for advice.