Which phrase accurately characterizes sexually transmitted infections (STIs)? are caused by bacteria, viruses, or parasites
always cause visible symptoms
are rarely transmitted by sexual contact
can be contracted only by women .

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c.carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit