What are the Disadvantage of hunting and gathering?

Please help me

If a swimmer is traveling at a constant speed of 0.85 m/s,how long would it take to swim the length of a 50m olympic sized pool?

Why were so many distinctive cultures able to develop over time in asia?

Which of the following studies is linked most directly to the establishment of the national research act in 1974 and ultimately to the belmont report and federal regulations for human subject protection? a. the public health service tuskegee study of untreated syphilis in the negro male.b. stanford prison experiment (zimbardo).c. tearoom trade study (humphreys).d. the harvard t3 study.