1, starch:Cons: mildew prevention technology has not been resolved, and the cost is too high, and even if technically, because our country is a food-deficit country, it is difficult to form a market.2, bi-degradable plastics:Cons: such utensils just added photosensitizer and starch to plastic, part of biodegradable, plastic parts cannot be degraded, so it's not a true green product, should not be promoted.3, pulp type:Cons: a, a paper lunch box weighs 25 grams, cost 0. 35 dollars, Nissan...