阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

The Amber Room was 【小题1】 gift that Frederick William Ⅰ, the King of Prussia, gave to Peter the Great. 【小题2】 return, the Czar sent him a troop of his best soldiers. The Amber Room which 【小题3】 (take) the country’s best 【小题4】 (artist) about ten years to make was a treasure 【小题5】 (decorate) with gold and jewels.

So it served as a small reception hall for 【小题6】 (importance) visitors. 【小题7】 (late) it was moved to a palace outside St. Petersburg 【小题8】 Catherine Ⅱ told her artists to add more details to it. 

It was completed in 1770 and was considered one of the wonders of the world. But after September 1941, when the two countries were 【小题9】 war, it was 【小题10】(miss). What happened to the Amber Room remains a mystery.