单级单吸离心泵的填料函的作用是防止空气进入泵壳和泵内液体大量漏出。
参考答案：对
高血压病引起心脏改变的特征是
A．左心室扩张B．左心室向心性肥大C．心壁肉柱扁平D．弥漫性心肌纤维化E．以上均不是
What a low opinion she ___ of him! He doesn't think it much good ___ friends with her.[ ]
A. thinks, to make
B. has, making
C. thinks , making
D. has, to make
