题干
如图，已知AD∥BE∥CF，
=
，DE=3，则DF的长为____ ．
| A |
| B |
| B |
| C |
| 2 |
| 3 |
答案(点此获取答案解析）
7.5
| A |
| B |
| B |
| C |
| 2 |
| 3 |