WE HAD TO WAIT... WE ARRIVED EARLY. (BECAUSE/ SO)

7 - - BAI TAP TU LUAN TIENG ANH LOP 9 UNIT 7 SAVING ENERGY
Lớp 9 BAI TAP TU LUAN TIENG ANH LOP 9 UNIT 7 SAVING ENERGY

7 - We had to wait... we arrived early.

(Because/ so)