—The Mars-500 test will take about 520 days.

—__________  I hope it goes well.

A. It’s a pleasure.    B. Good luck!     C. That’s OK.    D. Congratulations!

---The Mars-500 test will take about 520 days.
---______  I hope it goes well.

1. A.
   It’s a pleasure
2. B.
   Good luck!
3. C.
   That’s OK
4. D.
   Congratulations!

—The Mars-500 test will take about 520 days.

—__________ I hope it goes well.

A．It’s a pleasure.     B．Good luck!      C．That’s OK.      D．Congratulations!

—The Mars-500 test will take about 520 days.
—__________  I hope it goes well.