This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to use a biscuit joiner
Align the pieces of wood you want to join.
Make marks at the places where biscuits will be placed.
Use as many biscuits as needed to secure the pieces of wood.

Options are: 1). If you add too many together, one piece of wood could seem straight and sturdy. Pencil marks are also a good way to do this.. 2). Connect along the marks with wooden stakes and screws. Roll the wood over to ensure the pieces connect.. 3). Smooth rough edges with fine-grit sandpaper. Lacquer is alkaline and helps the wood absorb the sandpaper.. 4). Mark the other piece of wood at the same locations. The biscuit process allows some leeway in aligning the pieces of wood, so perfect alignment is unnecessary..
The answer is:
4).