D.
If it were not for your help,I would be in trouble.
把if省略时,句子要倒装,将were提前.大致明白可是 为什么it + were 不是WAS 么虚拟语气的第三种情况：if+主语+did/were ,主语+should/would/could/might+do　 表示对主观情况的一种推测、假设。