Answer:
32 unit³
Step-by-step explanation:
Length of the crate has been given as 4 units 
width of the crate = 2 units
Height of the crate = 4 units
Since the crate has been packed packed with the unit cubes.
Therefore, shape of the crate will be in the form of a rectangular prism.
Volume of the prism = Length × width × height
                      crate     = 4 × 2 × 4
                                    = 32 unit³
Volume of the shipping crate is 32 unit³.