说到病菌,通常指的是那些能使人得病的细菌和病毒。这些微生物太小了,即使用放大镜也看不见,却常令我们害怕。人的眼睛只能看清直径200微米以上的物体,那大概是你一根头发的粗细。大多数细菌只有1微米大小,200个细菌并排才有人类头发直径那么长。想看到细菌,就需要使用光学显微镜。在显微镜下,有些细菌像小球,有些像小棒,还有些螺旋形 Speaking of germs, usually refers to those that can make people sick bacteria and viruses. These microbes are too small to see even with a magnifying glass, but we are often scared of them. People’s eyes can only see the object more than 200 microns in diameter, it is probably the thickness of your hair. Most bacteria are only 1 micron in size and 200 bacteria side by side have the human hair diameter so long. To see the bacteria, you need to use a light microscope. Under the microscope, some bacteria like pellets, some like small sticks, but also some spiral