TOEFL Reading: ETS-TOEFL阅读机经 - F5FI5LV0W80J436GL$

Select the TWO answer choices that, according to paragraph 5, indicate true statements about sub-Saharan slash-and-burn agriculture. To obtain credit you must select TWO answer choices. A. It involved a careful selection of soils for cultivation. B. It involved regular flooding of the soils to improve fertility C. It was abandoned after being implemented intensively for two centuries. D. It spread quickly once it took hold.