Las siglas WWW ¿Qué significan?

Which of these is most responsible for differences between the twentieth century to the twenty-first century?

In which part of a professional email should you try to be brief, but highly descriptive?

Which of the following is not a way in which trees benefit the environment? a. they remove a significant amount of carbon dioxide from the atmosphere. b. they remove a significant amount of oxygen from the atmosphere. c. their roots hold soil in place, reducing rates of erosion. d. they remove ozone and particulates from the atmosphere. select the best answer from the choices provided a b c d