Examples: Cotton, linen, china, paper, sugar, tea, coffee, cereals, flour.
4. The household products that are exported.
Nature Study.—1. The parts of plants used as food.
2. The natural sources of our common foods, such as cornstarch, flour, breakfast cereals, tea, coffee, cocoa, sugar, salt, cheese, butter.
3. The sources of common household substances, such as coal-oil, gasolene, paraffin, turpentine, washing soda, whiting, bathbrick, soap.
4. The forms of water, as ice, steam.
5. The composition and impurities of the air.
6. The ordinary woods used in house building and furnishing.