1 . It has four Roll-Royce Merlin engines, but the group will need to have only three of them rebuilt. ____________ when they broke open the packing cases and found that the fourth engine was sweet as honey-still in perfect condition.（根据句意填空）

2 . 因为缺乏历史依据，难以想象这个国家六世纪的生活是什么样的。
_____ _____ _____ _____ what life in the country was like in the 6th century because there is a lack of historical evidence.

3 . Frederick WilliamⅠ, the King of Prussia, could never___________________(imagine)(绝不可能想到）that his greatest gift to the Russian people would have such an amazing history.

4 . 正如你能想到的那样，没有高薪的工作很难在大城市生活地舒服。
________________, it is very difficult to live in comfort in a big city without a well-paid job. ( imagine )