高速钢刀具磨损的主要原因之一是硬质点磨损。( )
参考答案：对
The 18 college students in Fudan University should______________show their greatest respect to
their hero--'Zhang Ninghai instead of being cold and unfeeling. [ ]
A. absolutely
B. slightly
C. fluently
D. painfully
下列反应中，属于吸热反应的是
A．乙醇燃烧
B．氧化钙溶于水
C．碳酸钙受热分解
D．盐酸和氢氧化钠反应
