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参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【简答题】质量为m的木块静止在一固定的斜面上，已知动摩擦因素为μ，斜面倾角为θ，木块所受摩擦力为（ ）
A.
μmgcosθ
B.
μmgsinθ
C.
mgcosθ
D.
mgsinθ
【单选题】Can trees talk Yes, but not in words. Scientists have reason to believe that trees do communicate with each other. Not long ago, researchers learned some surprising things. First, a willow tree attack...
A.
touching one another
B.
C.
B. smelling one another
D.
C. making unusual sounds
E.
D. making special movements