________ the professor did all he could to help, the experie
| ________ the professor did all he could to help, the experience failed eventually. |
| [ ] |
| A. Since B. When C. While D. As |
可能相似的问题
你能帮帮他们吗
| ________ the professor did all he could to help, the experience failed eventually. |
| [ ] |
| A. Since B. When C. While D. As |
你能帮帮他们吗