Any substance, such as a drug, chemical, or virus that can bring about a birth defect?

Chronic illness it is a permanent change ? true/false

Which statement about consumer rights is true? only celebrities have the right to complain about products that do not work. consumers can always get their money back if they dislike a product purchased. consumers are not allowed to complain about a product after it is purchased. everyone has the right to participate in making laws that affect consumers.

How do the uv rays cause damage?   what exactly causes the skin to burn;   can you be more specific about this mechanism?   3. how do photosensitive medications increase a person's sensitivity to sunlight and therefore increase their risk of getting burned?     what kind of medications can increase photo-sensitivity, can you think of some examples?