The experiment is of particular importance.

—I see. We will carry on with it ________ we can get enough money.

 —The experiment is of particular importance.

—I see. We will carry on with it ________ we can get enough money.

  A. unless        B. though            C. whether            D. until

---The experiment is of particular importance.

---I see. We will carry on with it ______ we can get enough money.

1. A.
   unless
2. B.
   though
3. C.
   whether
4. D.
   until

---The experiment is of particular importance.
---I see. We will carry on with it ______ we can get enough money.

1. A.
   unless
2. B.
   though
3. C.
   whether
4. D.
   until