A: What did you buy in the Computer World yesterday?
B: ____  I want to use it to record.
A: ____ 
B: Well, I haven't known yet.____  
A: Oh, no! You should read the instructions first.
B: If you want to turn on the recorder, press the blue button”.
A: Look! It works. How do you save your video?
B: ____ 
A: You've done that! Let’s try something to record.