Students can easily fall behind in their studies ____ they don’t manage their spare time carefully.
After two years’ research, we now have a ____better understanding of the disease.
The 44-year-old Cameron, ______ youngest British Prime Minister in nearly 200 years, wants to improve Sino-British relations to ______ new high.
-- Brad was Jane’s brother! -- ____ he reminded me so much of Jane.
______! The rescue workers are coming.
---- David has made great progress recently. ---- ________ and ________.