【正确答案】 A

【答案解析】[解析] 句意为：要不是你的帮助，我就不会提前完成这项工作。If条件句可与but for, without, otherwise, or等短语转换，此句可转换为if非真实条件句为“If I hadn"t had your help, I wouldn"t have finished the work ahead of time”。此句为对过去的虚拟，主句谓语动词用would/should/could/might+have done，故答案为A。