Given more time and money,they would have done it better.如果给他们更多的时间和金钱,他们就会做德更好这里面好象是省略的一个条件状语从句,如果补充完整是 1.if they were given ...还是2.if they had been given...两个都可以还是只有其中一个正确啊?如果是1,if可以一起省略吗?这种情况只能省略主语和be动词啊如果是2,那就是一个虚拟语气,能这样省略吗?但我还是不大明白，这里given more time and money究竟是不是由状语从句省略了而来的,为什么能够省略成只剩下given...那if和句子的主谓呢?能全省了吗?

第二个不行。if不能省略

你说的两句都不成立。完整的应该是：
If they had given .... They would have done....
虚拟语气-if从句 与过去事实相反：

从句用过去完时 主句用过去将来完成时

If＋主语＋had done... 主语＋(should/would) have done
e.g
If you had been there last night, nothing would have happened. 如果昨晚你在那儿，什么事也不会发生。

if they were given more time and money 。。。
和
if they had been given more 。。。
两个都对
如果要省略if，句子就要改
had they been given more time and money，they would have done it better
我不懂什么是状语从句，总之
Given more time and money, they would have done it better.
就等于我上面所说的
（had they been） given more time and money，they would have done it better
一看就懂这意思，你不也是翻译对了吗？
had they been 这里可以省略是因为后面有they would have

2.if they had been given...
应为后半句有have所以前面要有had。虚拟语气结构的规定。
if 不能单独省略。
Given more time and money, they would have done it better.
你说对了。if和句子的主谓全省了.是从if they had been given..得到的。
至于为什么能够省略成只剩下动词given，是英语使用的习惯。

是1答案
因为与过去事实相反所以要用到一般过去表虚拟 也就是 if they were 不要误以为这里是真正一般过去时 这只是凑巧都用were而已.
2答案肯定不对了 if+have done 是对于现在的情况的虚拟 所以不能选
定式就是这样的.,
建议多做专题强化 我就是靠题目把英语搞起来的