吸出高度为正值时水轮机空蚀减轻。
参考答案：错
属于经线的是（ ）
A．赤道
B．南极圈
C．北纬40°
D．本初子午线
—Do you remember _______ came to our city?
—Yes. On December 25 last year.
A. when the singing star
B. how the movie star
C. why the famous speaker
