—You probably won't need to call Joe, but take his number, just ________.
—Thanks a lot.
A．at random B．in return
C．in case D．by heart
If we ________ one of the other uploading approaches, the process would have taken longer than one hour.
A．used B．had used
C．should use D．would use
For Wang Shun，________ university graduate from China's less developed Guizhou Province，shopping online is ________ delight as she tries to keep pace with the lives of those in big cities.
A．the；a B．a；不填
C．an；a D．a；a
The urge to go abroad for further study is strong, but it was not until last summer ________ I knew how powerful it could be.
A．who B．that
C．where D．before
Only when I put myself in their position ________ they were more miserable than me.
A．I had known B．had I known
C．I knew D．did I know
China added 50.9 million Internet users in 2012，________ the total to 564 million at the end of last year.
A．brought B．bringing
C．having brought D．to bring
