---It’s a long time ________ I last saw you．

---Yes, and it will be another month ________ we can meet again．

1. A.
   before; since
2. B.
   when; before
3. C.
   since; when
4. D.
   since; before

---It's a long time _____ I last saw you．
---Yes, and it will be another month _____ we can meet again．

1. A.
   before; when
2. B.
   when; since
3. C.
   since; while
4. D.
   since; before

------ It's a long time _____ I last saw you．
------Yes, and it will be another month _____ we can meet again．

---It’s a long time ______ I last saw you.

---Yes, and it will be another month ______ we can meet again.

---It’s a long time _________ I last saw you.

---Yes, and it will be another month ________ we can meet again.

A．before；since          B．when; before           C．since; until       D．since; before