1,Your car has a white colour, 
A. Hasn't it
B. Doesn't it
C. Has it
D. Does it
2,       , he will have a party with friends
A. Once he gets his first job
B. When he got his first job
C. As he got his first job
D. After he had got his first job
3, Two renowned researchers at Oxford University    this scientific theory
A. Upgraded
B. Enlarged
C. Magnified
D. Advanced
4,  Name was too tired, so he went to sleep  lunchtime
A. For
B. On
C. With
D. At
5,  a Master's at Cambridge University, he returned to his country and established his own company
A. Has done
B. Having done
C. Have been done
D. Having been doing
6, Last Saturday, Susan  some old friends and they had a long conversation with each other
A. Cut down
B. Put off
C. Came across
D. Brought off