新东方考研英语必背500句
第155句
as so often, the past holds the key to the future: we have now identified enough of the longterm patterns shaping the history of the planet, and our species, to make evidence-based forecasts about the situations in which our descendants will find themselves.
译文：如常所见，过去决定未来：现在，我们已经充分确认了形成我们这个星球及其物种的历史的长期模式，这足以让我们有据可依地预测我们的后代将身处怎样的境地。
点睛：本句的主干是the past holds the key．冒号后的内容是对前面句子主干的解释和说明，也是一个完整的句子，主干是we have identified enough，而of the long-term pattern作定语修饰enough，后面的不定式短语to make…forecasts…作目的状语，in which引导的定语从句修饰situations。
考点归纳：本句须注意as so often和hold the key to两个短语。
*as so often意为“一如往常，常常”。如：
as so often happens when i travel around the world, i was struck by people who are so kind to strangers.
正如我在世界各地旅行时经常遇到的那样，人们对于陌生人如此亲切让我感到非常吃惊。
*hold the key to意为“是…的关键”，其后接名词或动名词。如：
however, it is the symbols that may hold the key to understanding early human communication.
然而，或许正是这些符号才是理解早期人类交流的关键