It is generally believed that improper human activities contribute to global warming. But this belief is facing an inconvenient challenge after the release of new temperature data showing the planet has not warmed for the past 15 years. Based on statistics from more than 30,000 measuring stations, the data confirms that the rising trend in world temperatures ended in 1997. The figures also suggest that we could even be heading for a mini ice age comparable to the 70-year temperature drop in the 17th century.Meanwhile, climate scientists said that, after releasing unusually high levels of energy throughout the 20th century, the sun is now heading toward a “grand minimum” in its output (输出). This is likely to cause cold summers, bitter winters and a shortening of the season available for growing food.Solar output goes through 11-year cycles, with high numbers of sunspots (太阳黑子) seen at their peak. We are now at what should be the peak of what scientists call “Cycle 24”. But sunspot numbers are running at less than half those seen during cycle peaks in the 20th century. Analysis by experts suggests that Cycle 25, whose peak is due in 2022, will be a great deal weaker still.According to a paper published last week, there is a 92 percent chance that both Cycle 25 and those taking place in the following decades will be as weak as, or weaker than the period of 1790 to 1830. In that period, average temperatures in parts of Europe fell by 2℃. It is also possible that the new solar energy drop could be as deep as what happened between 1645 and 1715 when the canals of Holland froze solid.1. According to the author, which of the following views seem to be generally accepted but may now prove wrong?A) The sun output is getting weaker.B) The earth is facing a temperature drop.C) The sun output is getting more harmful.D) The earth is getting warmer and warmer. 2. According to the new temperature data, ____________.A) world temperatures will continue to riseB) world temperatures have not risen since 1997 C) world temperature will keep dropping for the next 70 yearsD) world temperatures have been dropping for the past 15 years3. Which of the following is implied, but not directly stated as a possible consequence of reduced solar output?A) Bitter winters.B) Cold summers.C) Shortened seasons.D) Reduced food production. 4. What can we learn about sun energy in the 20th century and 21st century?A) Solar output will reach its minimum in the 21st century.B) Solar output in the 20th century was the highest in history.C) Sunspot numbers in Cycle 24 has reached its peak in the 21st century.D) Sunspot numbers in Cycle 24 is less than half those in the 20th century. 5. What is predicted about solar energy in Cycle 25?A) Cycle 25 may be stronger than Cycle 24.B) Cycle 25 may be weaker than the following decades.C) Cycle 25 may be as weak as the period of 1645 to 1715. D) Cycle 25 may be stronger than the period of 1790 to 1830.