So difficult ___it to work out the problem that I decided to ask Tom for advice.
Victor apologized for ____ to inform me of the change in the plan.
I smell something ____ in the kitchen. Can I call you back in a minute?
——Let’s go to the movies after supper. OK? ——_______________.
Mary came in , _____ by her dog.
I failed in the final exam last term and only then ______ the importance of studies.