67 million years ago in the form of phyollths (small sllica flecks in grass that make it difficult to digest)
The answer is different magnification lenses. Leeuwenhoek use a microscope with different magnification lenses which enabled him to see bacteria. <span>His microscope was able to achieve 50-300x magnification, which enabled him to see a variety of bacteria.</span>
The answer u r looking for is- D, Nuclear Envelope. Hope I’ve helped ;)