问题详情：
根据句意用所给的单词的适当形式填空。
1. The UK is an old ____ (Europe) country, where there are many palaces and castles.
2. Marie Curie and her husband won the Nobel Prize in 1903 for the __________(discover) of radium .
3. The population on the Earth is still increasing ____________(rapid).
4. Jimmy lives on the ________ (nine) floor of the new building.
5. ---Who’s that boy standing over there?
----Sam, a foreign friend of ________.( I )
【回答】
1. European 2. discovery 3. rapidly 4. ninth 5. mine
知识点：构词法
题型：完成句子
