17.Cutting trees in half can help scientists understand the past and now it appears it can be used to predict the future.Researchers have been looking at ring growth from trees to make sense of past weather patterns such as droughts and rain.
Combining data from the rings allowed them to create a copy of pictures of climate changes over the past 2,000 years and this information could also be used to foresee future famine(饑荒),unrest and conflict.The project has been named Old World Drought Atlas,or OWDA.
Its main author,Columbia biologist Edward Cook,has already carried out similar projects using trees to create chronological(按順序排列的)maps of drought in Asia and North-America.He believes that combining the three atlases could throw light on the global causes of drought and climate change.
The study,for instance,gave special attention to the importance of one of such causes,the North Atlantic Oscillation(濤動(dòng)),in affecting climate patterns in Europe,and specifically in making Europe wetter north of the Alps and drier south of them.
The OWDA also helped analyse historical events from a climatic perspective.For instance,the 1740-174lfamine in Ireland had so far been explained by an unusually cold winter and spring,but the atlas shows that unusually low rainfall over the spring and summer of 1741 could also have played a role.Finally this made growing food nearly impossible and caused a continent-wide famine.
A better grasp of these processes could even make it possible to predict future famine,unrest and conflict.
Cook said,64The Old World Drought Atlas fills a major geographic gap in the data that's important to determine patterns of climate changes in time.That's important for understanding causes of many droughts,and it's important for climate modelers to test hypotheses(偎說) of climate forcing and change.
32.Why is ring growth useful in research?B
A.It's the best way to understand the past.
B.It could be used to predict the future.
C.It could be used to prevent the outbreak of droughts and rain.
D.It isn't mentioned in the passage.
33.People worldwide can read chronological maps of droughtA.
A.in Asia B.in Africa
C.in Europe D.in South America
34.What is the author's attitude toward the study of OWDA?C
A.Positive.B.Negative.
C.Objective.D.Conservative.
35.Why did the author of the passage mention what Cook said?B
A.To show he interviewed Cook himself.
B.To tell us the importance of OWDA.
C.To compare climate variability.
D.To analyse how to predict droughts.