从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
6. ---You couldn’t have chosen any gift better for me.
---_________________
A. Oh, I’d choose a better one for you next time.
B. You’ve had gift for music, haven’t you?
C. I’m glad that you like it so much.
D. Sorry, but don’t blame me, dear.
7. It was not until they reached the river ________ they found the bridge had been washed away.
A. when B. while C. that D. which
