The authors show that the hyperboloid of one sheet and the hyperbolic paraboloid are ruled surfaces.作者证实:单叶双曲面和双曲抛物面是直线曲面.Two fdmilies Of characteristic lines in the hyperbolic region are not orthogonal.在双曲型区域两族特征线互不正交.F...
说来也怪，他最后想到的才是他心爱的塔尼娅。Strangely enough, the last thing he thought of was his beloved Tanya.两个刀架上存放着她最心爱的刀具。Two knife racks hold her favourite knives.失去心爱的人是无法补偿的。Nothing can compensate for the loss of a loved one....