What types of flowers produce the most nectar?

9. the history of life on earth is recorded in

Which was most likely an effect on society that resulted from improvements in blood handling during world war i and world war ii?

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled