$17.$ True or False: Solvent recovery is an unnecessary step in the extraction process.

$18.$ True or False: Continuous contact extractors do not allow for the recycling of solvent within the system.

$19.$ True or False: The choice of solvent has a significant impact on the environmental footprint of the extraction process.

$20.$ True or False: Co$-$current and counter$-$current extraction methods can be applied interchangeably without affecting the outcome.