be preparing for和be prepared for的区别

They might very well be preparing for it,he thought.
他想,他们非常可能己经在做准备了.
We must always be prepared for every contingency.
我们必须始终做应急准备.
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prepare + 双宾语（间接宾语和直接宾语）.例如：
Mother is preparing us a meal.= Mother is preparing a meal for us.
母亲正在为我们做饭.
The secretary has prepared the president a long report.= The secretary has prepared a long report for the president.
秘书已为董事长准备好了一份长篇报告稿.
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过去分词 prepared 用于系表结构,意思为“为……做好准备；打算”,常用于以下句式：
1.be prepared + for （或 against ）引起的短语.例如：
They were prepared for the worst.
他们已准备好应付最坏的情况.
I knew there were problems,but I was not prepared for this.
我知道有些问题,但却未防范这一点!
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感觉这个说的不错.