Which event occurred during the mesozoic era? a. humans lived on earth. b. the first plants lived on the land. c. pangaea, the super continent, began to break apart. d. cyanobacteria begin to fill the air and water with oxygen.

answer; i believe that the best answer is (secondary cardiac arrest due to

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.

condenser is used to focus in the light microscope.

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i don't understand your question