题目

My brother is handsome and ________, but sometimes he is not _______me.   A. energy; patience with             B. energetic; patient to   C. energy; patient with              D. energetic; patient with   答案：D一块重6N、边长为10cm的木块，用8N的竖直向上的力压在天花板上．则木块对天花板的压力为    N，木块对天花板压强是    Pa．