After the earthquake, the president _____ a three-day period of mourning, the first-ever event of its kind for ordinary people.
This kind of bird is ___________ , and we should do what we can to it.
Believe it or not, Levy’s sister suddenly ___________crying when we ere eating.
To our___________, Jane’s illness proved not to be as serious as expected before.
A new situation is likely to ___________when the school leaving age is raised to 16.
Last summer I took a course on___________poisonous gases.