25. The pen I _____ I_______ is on my desk, right under my nose.
A．think...lost B．thought...had lost
C．think...had lost D．thought...have lost
【答案】B
【解析】考查时态：语境为：我原以为丢了的确在鼻子底下。可知是过去以为，所以第一空填thought，而丢失这个动作是发生在thought前，用过去完成时：had lost，选B。
26. ______ at the top of the Oriental Tower, people below will look very small.
A．Stand B．Standing
C．To stand D．If you stand
【答案】D
【解析】考查句子成分：句意：如果你站在Oriental塔顶，下面的人会看起来很小。这句话的主语是people below，但是前面的动作stand不是people below发出的，所以不能用非谓语动词做状语，应该是条件状语从句，选D。
27. _____ from other continents for millions of year, Australia has many plants and animals not found in any other country in the world.
A．Being separated B．Having been separated
C．Having separated D．To be separated
【答案】B
【解析】非谓语动词用法的考查；通过分析句子结构，这里需要用现在分词作原因状语，现在分词的动作发生在谓语动作之前，故用现在分词的完成时；并且现在分词的逻辑主语“Australia”与分词动作“separate”
