往复泵的水力损失表示所输送液体在管路中的摩擦损失与局部阻力损失。
参考答案：错
解析：往复泵的水力损失表示液体在泵内运动时的摩擦损失和局部阻力损失。
It was _____ he came back from Africa that year _____ he met the girl he would like to marry.[ ]
A. when; then
B. not; until
C. not until; that
D. only; when
简述教育经费的衡量指标。
