| 1. | He proved the existence of parallel lines .
他证明了平行线的存在性。 |
| 2. | Parallel lines indicates a break in continuity .
平行线表示连续的中断。 |
| 3. | A family of parallel lines cut the conic .
有一组平行线与圆锥曲线相交。 |
| 4. | Consider a family of parallel lines that cut the conic .
设有一组平行线与圆锥曲线相交。 |
| 5. | One of the five parallel marks constituting a staff
谱线五线谱上五条平行线中的一条 |
| 6. | Will the sum of the lengths of these segments be finite
问，这些平行线段的长度和是有限的吗？ |
| 7. | Love can only become eternal parallel lines thereupon right away
于是爱情就只能成为永远的平行线。 |
| 8. | Parallel angles or lines run from important tops and bottoms
平行角或平行线从重要的高点和低点开始起作用。 |
| 9. | Parallel lines converge at infinity
平行线永不相交 |
| 10. | One of a set of parallel geometric figures , such as lines or planes
平行线，平行面如直线或平面等一组平行的几何图形之一 |
