To tell you the truth, I have a hard time remembering all the ______ rules of English grammar.
I find painting and listening to music __________.
—I usually go there by train. —Why not __________ by boat for a change?
Having been ill in bed for nearly a month, he had problems __________ the exam.
It was so dark that he __________.
The Wangs are considering __________ to Huangshan for a trip at five tomorrow morning.