【官方真题Official托福阅读】官方真题Official3托福阅读词汇真题练习——unprecedented&virtually

在托福阅读备考过程中，词汇题是阅读题中必考的一个部分，而想要成功答对所有词汇题，并非仅从词汇量一个方面入手就可以。那么，在以下方面，我们就为大家带来一些官方真题Official中的经典词汇题，大家不妨来练习一下吧。

Paragraph 4: This unprecedented development of a finite groundwater resource with an almost negligible natural recharge rate—that is, virtually no natural water source to replenish the water supply—has caused water tables in the region to fall drastically. In the 1930s, wells encountered plentiful water at a depth of about 15 meters; currently, they must be dug to depths of 45 to 60 meters or more. In places, the water table is declining at a rate of a meter a year, necessitating the periodic deepening of wells and the use of ever-more-powerful pumps. It is estimated that at current withdrawal rates, much of the aquifer will run dry within 40 years. The situation is most critical in Texas, where the climate is driest, the greatest amount of water is being pumped, and the aquifer contains the least water. It is projected that the remaining Ogallala water will, by the year 2030, support only 35 to 40 percent of the irrigated acreage in Texas that is supported in 1980. 【官方真题Official3- Depletion of the Ogallala Aquifer】

6. The word “unprecedented” in the passage is closest in meaning to(3)

○difficult to control

○without any restriction

○unlike anything in the past

○rapidly expanding

7. The word “virtually” in the passage is closest in meaning to (4)

○clearly

○perhaps

○frequently

○almost

答案：(4)