题型:问答题 简答题 如图为碳循环示意图,据图分析(1)碳循环是以______的形成进行的.(2)二氧化碳是通过______作用流向B的.(3)二氧化碳从A.B.C流向大气是通过______作用实现的(4)A.B.C分别属于生态系统的成分是______、______、______. 查看答案
题型:问答题 简答题 --- Why didn’t Tom give you one of his paintings? --- I didn’t want one, but he would have given me one if I______.A.did B.wouldC.willD.had 查看答案