__________ medical science has achieved control over several dangerous diseases, what worries us is that some of them are returning.
---How far do they live apart? ---I know, they live in the same neighborhood.
Even students withintelligence can be excellent students after improving their study habits.
With exportsan important role in its economic growth now, this province has been affected by the global economic downturn.
—Will you go to the party tomorrow, Xiao Hai? —No, ____ I was invited to.
Only when the firefighters put off the firewhat great damage it caused.