()是热交换的推动力()是湿交换的推动力。
A.温度,水蒸气分压力
B.温度差,水蒸气分压力
C.温度,水蒸气分压力差
D.温度差,水蒸气分压力差
参考答案:D
点P(0,1)在函数y=x2+ax+a的图象上,则该函数图象的对称轴方程是______.
Picking apples _____ more interesting than _____ lessons. [ ]
A. are, having
B. is, having
C. are, have
D. be, having