Answer:
Electron microscope is a device which is used to see microscopic objects using electon. In this tyoe of microscope electron is thrown on an object whose image is formed on the screen. It resolution power is 10,000X. If the internal structure of an object is to be observed then SEM is used, however for three dimensional structure, TEM is used.
The porcupine is a rodent with an unusual trait. Porcupines have sharp spines or quills that help protect it against its predators. This trait is different from other rodents because of its needle like quills. This animal is also similar to that of a hedgehogs.
Answer:
<u><em>C.)</em></u> <em>Crest to trough</em>
