---How did you work out the difficult chemistry problem?
--- I worked it out by ________.
A.working with a group | B.think very hard |
C.ask the teacher for help | D.doing oneself |
---How did you work out the difficult chemistry problem?
--- I worked it out by ________.
A.working with a group | B.think very hard |
C.ask the teacher for help | D.doing oneself |