省煤器放水门的位置？
参考答案：
炉12．6米层疏水母管。
— I wonder what I should learn in the future.
— You may learn art since you ___ painting and drawing. [ ]
A. benefit from
B. have a gift for
C. look forward to
D. are tired of
等高线的垂直间距相等且平行于（）
A.自然地貌
B.地面
C.水平面
D.地形
