The correct answer is coupons and comparative shopping.
Coupons are commodities that give consumers a saving on the purchase of an item(s) at particular stores. These coupons help individuals to save money. Comparative shopping works in a similar way. However, instead of having a physical coupon to show, consumers can compare prices of goods from different stores using resources like newspaper advertisements or online databases.
Opportunity costs and marginal benefits have nothing to do with saving money. Rather, these deal with other economic principles like choosing between different options and the additional satisfication that a person gets from consuming more of a good.
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.
Total Internal Reflection
Bill Hammack of the Department of Chemical and Biomolecular Engineering University of Illinois-Urbana discusses Total Internal Reflection. It is the mechanism wherein light trail liquid flowing. It is the process by which light entering the stream is reflected when it strikes the juncture between air and liquid.
In psychophysics, experiments seek to determine whether the subject can detect a stimulus, identify it, differentiate between it and another stimulus, or describe the magnitude or nature of this difference. Software for psychophysical experimentation is overviewed by Strasburger.
