What happened to many people 100 years ago when they got a cold? How did chemistry help this situation?

If two parents who's blood types are both b produce a child that has blood type o, what can you say about the parent's genotybes? oa) one is ii ob) one is ibi oc) both are bi od) nothing, this is impossible

Regarding most of the narrator’s story, which word best describes the tone?

If a strand of dna has 35% thymine. what is the percentage of cytosine, adenine, guanine?