讲解：

offer sth / sb (up) (to sb)
奉献,祭献(给上帝):
We offered up our prayers for the men's safe return.
我们祈求上苍保佑他们平安归来。

be complicated
复杂的；难懂的
It's all very complicated—but I'll try and explain.
尽管这一切都很难理解,但我会尽力解释。

once+句子
一…就；一旦；当…时候:
We didn't know how we would cope once the money had gone.
一旦钱花光了,我们就不知道该怎么办了。

a rich moist cake
松软味浓的蛋糕
Add some water to keep the cake moist.
加点水来让蛋糕松软。

prosperous countries
繁荣的国家
China has became prosperous over the past 30 years.
中国在过去的三十年里变得十分繁荣。

import sth (from...) / sth (into...)
进口；输入；引进:
The country has to import most of its raw materials.
这个国家大多数原料均依赖进口。

pour sth into/over/介词
使(液体)连续流出；倾倒；倒出:
Pour the sauce over the pasta.
把酱汁浇在麪食上。