39. _______ is certain, people’s living conditions in China have improved a lot since the 1980s.
Their classroom is _____ than ours, that is to say, their classroom is as small as ours.
It was _____ it raised so many difficult questions _____ the book took a long time to come out.
It is sometimes of great _____ to explain to the patient what is happening.
The failure of his plan made him _____ that he had made a great mistake in working out the plan.
—I’d like to book a single room in your hotel. —OK. They’re US$100 each, but a room with a sea view will cost _____ $10.