水泵的基本性能有:流量、扬程、()、效率、转速、允许吸上真空高度等。
参考答案:轴功率
— Your English has improved a lot . How do you learn it ?
— I learned by __________the textbook.. [ ]
A. read
B. reading
C. look
D. looking at
教育要适应个体身心发展的不平衡性、顺序性、阶段性、互补性和_______。