—The guard keeps watch at the gate.—So he does. Only those knows well could be let in.
What the boy enjoys _____ to have a room of his own.
Which do you enjoy ____ your weekend, swimming or fishing?
I think this is the very work that we must finish ____ her.
The work he devoted his time to _____ worth praising.
The theory he sticks to ______ to be of no use in our studies.