The cleaning process is used to eliminate smudge and dirty grit. Because this dust can cause damage to the lens if reused, hence it is recommended that the wipe should be disposed of in order to prevent damage in later cleanings.
If you re-use it can have the possibility to smear oils from the fingers on the lens. Moreover, the dust from earlier used paper can damage the coating. Because the lens paper is like a paper sheet, once it is stained, you cannot use it again.
Answer: By Jacques-Loius David in 1784 and is now displayed in Louvre, Paris
Explanation:
His painting became popular due to the criticism he received and is among the popular Neoclassical style of paintings.
Answer:
Knowledge
Explanation:
Knowledge could be defined as information, facts, skills gathered through experience or education. In the case above, the student has knowledge of how his "class average" works and so he "knows" that if he works hard enough, he can improve it to a B. However if he didn't have this knowledge, he probably would have started panicking and already think there isn't any hope of improving his average.