______ on ten years of observation and study, the theory shows that every one dreams every night, whether they realized it or not.
33. We were to go out for a walk ________ it began to rain.
32._________on the lonely island_________more difficult than they had expected.
31. —How long_________each other before they_________married? —For about a year.
30. — Have you ever been to Australia? — Never, but I have been looking forward _______ such a chance for further study there.
29. —Shall I call you at 6 a.m., Toby? —No, not that early. I ____.