（一）

   The following appeared in a memo from the president of Viva－Tech， a manufacturer of high－tech medical equipment.

　“In order to reduce costs， we should close some of our existing small assembly plants and build a large central plant. Grandview would be an ideal location for this new plant. First， of the locations that we have considered， Grandview has the largest adult population， so that we will be able to staff our plant quickly and easily. Second， since the average wage earned by workers in Grandview is less than that in the other locations， we should be able to keep production costs low. Last， as an inducement for us to build there， Grandview’s town council has offered to allow us to operate for the first three years without paying city taxes.”

（二）

  It is known that in recent years， industrial pollution has caused the Earth’s ozone layer to thin， allowing an increase in the amount of ultraviolet radiation that reaches the Earth’s surface. At the same time， scientists have discovered， the population of a species of salamander that lays its eggs in mountain lakes has declined. Since ultraviolet radiation is known to be damaging to delicate tissues and since salamander eggs have no protective shells， it must be the case that the increase in ultraviolet radiation has damaged many salamander eggs and prevented them from hatching. This process will no doubt cause population declines in other species， just as it has in the salamander species.

（三）

  The following is a letter to the head of the tourism bureau on the island of Tria.

　“Erosion of beach sand along the shores of Tria Island is a serious threat to our island and our tourist industry. In order to stop the erosion， we should charge people for using the beaches. Although this solution may annoy a few tourists in the short term， it will reduce the number of people using the beaches and will raise money for replenishing the sand. Replenishing the sand， as was done to protect buildings on the nearby island of Batia， will help protect buildings along our shores， thereby reducing these buildings’ risk of additional damage from severe storms. And since the areas along the shore will be more attractive as a result， the beaches will be preserved and the area’s tourist industry will improve over the long term.”

（四）

  A folk remedy for insomnia， the scent in lavender flowers， has now been proved effective. In a recent study， 30 volunteers with chronic insomnia slept each night for three weeks on lavender－scented pillows in a controlled room where their sleep was monitored. During the first week， volunteers continued to take their usual sleeping medication. They slept soundly but wakened feeling tired. During the second week， the volunteers discontinued their medication. As a result， they slept less soundly than the previous week and felt even more tired. During the third week， the volunteers slept longer and more soundly than in the previous two weeks. This shows that over a short period of time lavender cures insomnia.A folk remedy is usually a plant－based form of treatment common to traditional forms of medicine， ones that developed before the advent of modern medical services and technology.