According to the scientists, because of some damage, now Canada's forests ______. A.are greatly damaged by global warming B.approach the threatening line C.take in less carbon dioxide than they produce D.become net carbon sources
A.A.are B.approach C.take D.become
【参考答案】
C 解析：段中处及复杂句式处设题。本题考查加拿大森林目前释放和吸收二氧化碳的情况。解题关键在于理解now pum......