The answer to this question is:
Light (sunlight), water, and carbon dioxide! Oh, and chloroplasts.
Leukocytes are produced/stored in thymus, spleen, and bone marrow
The empirical formula of sulphur monoxide.
Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.
The answer would be skeletal markers and DNA analysis.
Skeletal markers are often used to identify the biological gender of skeletal remains. The most commonly used skeletal markers can be observed in the skull and in the pelvic bone.However, the accuracy of his method is limited to adults only the differences between male and female skeletal markers usually become visibly only after maturation.
DNA analysis is more widely uses nowadays because with the technology of today, laboratories can now detect and X and Y chromosome-specific sequences, which help them identify the biological gender.