What is the top most layer of earth that is extremely dense and only somewhat thick

Which best example best demonstrates the importance of having knowledge of evolutionary relationships? a. illustration of a plant b.organ transplantation between species c. blood donation from a human d. do you need sequence of an insect.

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes

Describe how viruses and bacteria can be used as biological weapons. what are some of the potential threats and potential benefits? do you agree with the use of viruses and bacteria as biological weapons? why or why not?