—Haven't you realized the use________the used paper?—Yes, already.
All of us found ______ difficult to work out the maths problem.
Doyouhappentoknow________?
Let Tom play with your toys as well, Clare—you must learn to_______.
Johnaskedme_______tovisithisuncle’sfarmwithhim.
The policeman warned the driver _______ so carelessly.