帮我分析一下这个英语句子，要高手啊，谢谢

Question

Those who were able took advantage of the opportunities for success and happiness that presented themselves.
这是《大学英语精读》里的一个句子，弄了半天没弄明白，感觉不像一个完整的句子啊，高手帮忙解答一下
我把整段话复制下来，参考一下：In addition, the time for changing one' s mind was over and gone and there was no question of ever returning to the paradise of home. Nothing lay ahead of us but exertion, struggle, and perseverance. Those who were able took advantage of the opportunities for success and happiness that presented themselves.

Answer 1

1. see 感观动词 + Ving 认为...

2. lose...to... 败给...；整句结构理解的关键在这里，"lose接连to"使用，表示"败给..."，这样后面"to possibly China"看来就不会那麼奇怪了；而要注意整句是个复合句，所以possibly副词(adv.)错位就近放置，否则一般简单句习惯上是放句尾的情况比较多。

3. amid (prep.) 处於(...环境下/...状况下)；其后所引导的介系词片语当作the United States的修饰语(补语)，用来说明the United States所处的环境状况，你也可以把amid换成under比较容易理解，amid就是个介系词(prep.)

4. 在修辞学上来看可以在amid前置一个"，"所有的问题就解决了；但一般文法上介系词前是无法这样做的。将整句重新改写重抄如下，看看是不是比较容易理解了：

Asians see the United States losing its undisputed international influence in 50 years to possibly China, amid waning trust in Washington to act responsibly in the world, a poll showed.

Answer 2

有才华的人会抓住转瞬即逝的机会为了成功。who were able是those的定语，be able 有才华的人 themselves指代opportunities，present=occur 出现的意思。意思就是机会不是你想让他出现就出现的。

Answer 3

此外，那些用来改变一个人心智的时间，已经一去不复返了。毫无疑问，还是回去那个天堂一样的家吧。

Answer 4

意思是说那些能够抓住出现的幸福和成功机会的人
presented themselves指的是success and happiness，也就是说success and happiness presented，成功和幸福出现

Answer 5

1 be able to 能够。。
2 those...took advantage of the opportunities for success and happiness.
3 that后修饰前面名词