Queen's Gambit Accepted - 4...e6
1. d4 d5 2. c4 dxc4 3. Nf3 Nf6 4. e3 e6
White moves the queen's pawn to d4. Black pushes the queen's pawn to d5. White plays the c-pawn to c4.
Black captures on c4 with the queen's pawn. White develops the knight to f3. Black develops the knight to f6.
White moves the king's pawn to e3. Black advances the king's pawn to e6.