（建议使用新世纪教材学生选做）Complete the sentences with the given words in their proper forms (用括号中所给单词的适当形式完成下列句子)：
【小题1】I have bought a new flat and it's on the ________ floor of the building.  (twenty)  
【小题2】I think they are old enough. They can look after ________. (they)   
【小题3】Be sure that you have all the facts before you take ________. (act)  
【小题4】The old man likes to travel ________ with the young. (wide)   
【小题5】I couldn't ________ whether he was brave or not. (decision)   
【小题6】Finally the factory stopped to ________ the river. (polluted)   
【小题7】She is a ________ woman who is certain of her views. (confidence) 
【小题8】To our ________, he is our teacher's husband. (surprised)