We are extremely grateful to you for the trouble you have taken on our behalf. 多蒙鼎力相助,不胜感谢。
Please use your powerful influence [great effort] to support us. 请鼎力支持。
牛津高阶第八版
美国韦氏词典
Dictionary.com
Free Dictionary
维基百科 (自由的百科全书)