Avoid plastic in general (Plastic is usually not recycled, despite what people say. It ends up in landfills, the ocean, or it is burned)
Don't buy fast fashion (Clothes that are made in bulk by factories usually in Bangladesh. They are trendy but bad for the environment. Instead, shop at thrift stores.)
Don't waste food! Stop throwing out those leftovers, and make sure you eat everything on your plate.
Try to switch to renewable energy. (Use solar panels or find lights that conserve energy. Also, these options most likely cost less :)
Try to cut back on your meat intake. (I am a pescatarian who loves meat. I started this diet in 4th or 5th grade because it was a dare. I know, it was a crazy dare, but hey I don't back down! It's been about 5 years now and I'm still going strong. If me - a meat lover - can do it, you can to :)
The Law of Definite proportions states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation.
Answer A touches on the topics of economics and industrial feasibility of the flu shot. B is more of an ethical / situational question. C is a social question. D is the only question which focuses on the science of microbiology and medicine.
