information in the long term memory can be recalles at a later time
网友回答
when needed 属于省略句,相当于when it is needed .
======以下答案可供参考======
供参考答案1:
D当有需要时，储存在长期记忆中的信息将会被再现出来。
D选项为when it is needed 的缩写，完整应该为information in the long term memory can be recalles at a later time when it is needed 。
供参考答案2:
其实D答案，也是省略了的，应该是when it is needed.B答案不能用to be 的形式。