TOEFL Reading: ETS-TOEFL阅读机经 - 1ODI8Q8038WE0M47L$

According to paragraph 1, the results of full-scale climate models are questionable in part because A. the supercomputers used for such modeling are large and complex B. thousands of calculations have to be performed to assess conditions C. past conditions cannot always be estimated accurately D. there are multiple ways to represent the same aspect of climate