10) Silk Farming (cultivating silk worms) 11) Plantation or Tree Farming (long term development of timber) 12) Extensive Pastoral Farming (eg Hill Sheep Farming) You could argue that fish farming should be in the list, but that is generally considered to be a separate category.
Chromexcel is registered trademark for a kind of aniline leather with a history of production that goes back over a century in the US.
A photocell is any of a wide range of sensors that react based on the presence of light or electromagnetic energy. They can be found in many different forms, from solar panels that use light to generate electricity, to photoresistors, which shift in resistance based on how much light is present.