问题
选择题
—____ do you go to your school library?
—Three times a month. [ ]
A. How long
B. How often
C. How much
D. When
答案
答案:B
—____ do you go to your school library?
—Three times a month. [ ]
A. How long
B. How often
C. How much
D. When
答案:B
(1)石羊河的总体流向为______________。从内、外流河类型看,该河为_____________河,判断理由是_____________________。
(2)材料二图中所示地层,埋藏越深,距今年代越_________;深度1.6米处是沉积___________,由此可推断该地的干湿状况,距今5000年前后比现在______________,理由是___________________________。
(3)该河流中下游地区的气候类型是___________,目前面临的最主要的生态环境问题是___________。
(4)为了防止该流域生态环境恶化,在农业生产中,应该采取哪些措施?
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