Đếm , phân loại và đánh số phân loại cho các nhiễm sắc thể trong hình

Which is the correct formula for photosynthesis

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above

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