—Will you see me off at the airport at ten tomorrow morning?—Sorry, I ________ a lecture then.
Which do you enjoy ____ your weekend, swimmingorfishing?
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.
The man you referred to _____ just now.