【简答题】阅读理解。 Beijing-old and new Fifty years ago, if you flew over Beijing and looked down on the city, it looked like an army camp. The whole city was laid out in regular squares. In the middle was the Forb...
【单选题】On which of the following assumptions is based the belief, that tree-ring thicknesses show links between solar periodicity and terrestrial climate?
A.
Solar-activity cycle existed m its present form. during the period in question.
B.
Average tree-ring thickness varies from species to species.
C.
Tree-ring thickness varies with changes in terrestrial climate.
D.
Both terrestrial climate and solar-activity cycle randomly affect tree-ring thickness.