1.He gave us a warning against placing confidence in people we did not know.

1.他告诫我们, 不要轻信我们不了解的人。

2.Zollner's illusion makes parallel lines seem to diverge by placing them on a zigzag-striped background.

2.将平行线置于锯齿形条纹背景上，左氏让平行线看起来不平行。

3.The unit is composed of hydraulic and double conic placing,hydraulic spading and drawing ,straightening,shearing,end stopping,coiling,feeding,dropping cart,ect.

3.机组有液,双锥放料,液引,送料,校直,剪切,阻尼,收卷,上料,下料小车等主要部件组成.

4.One of the big disincentives to placing weapons in space has been the technical difficulty and cost of such an enterprise.

4.一直以来，在太空部署武器的主要障碍之一就是技术难度以及该项事业的高昂成。