—Is there any vaccine(疫苗) against H1N1 flu that can be used on humans?—No, but scientists are working to develop ________ .
Britain, ______________many other industrialized countries, ______ experienced major changes over the past 100 years.
—The current European debt crisis is affecting many countries in the world. —Will it be at least several years __________ everything returns to normal?
--Your mum is very kind. --Yeah, My mum is pretty considerate, you know what,she always arranges everything around me.
_______________made our school proud in 2011 was ____________ more than 40% of the students had been admitted to key universities.
So far this year we ______ a fall in house prices by between 5 and 10 percent.