拖地法：原则上应（）挥动，擦痕呈横向一字型，在角落等处，可用直拖等相应方法，拖布从（）向中间施拖。
参考答案：左右；四周
Tom put his heart into the wildlife research, and finally, his efforts ________ him great success and fame.[ ]
A. saved
B. earned
C. made
D. offered
从蛋形消化池构造特点分析，下述( )结论是正确的。
A．在池壁上设肋，用来张拉，锚固预应力筋
B．环向预应力筋在肋上张拉，锚固；竖向预应力筋锚固在池壁上
C．所有预应力筋都在池壁张拉口上张拉，待张拉、锚固完毕后用混凝土封闭
D．双向预应力筋的曲线包角为120°
