题目内容：

根据下列句子所给汉语意思或提示，写出空缺处单词的正确形式。

1.Scientists are ________ (调查) into the cause of cancer.

2.To get the job done, one should be ________(精力充沛) and hard­working.

3.As a ______（奖赏）for passing her exams, she got a new bike from her parents.

4.Dilma Rousseff, who won 56% of the _______ (选票), was elected President of Brazil.

5.The old lady likes          (spy) into other people’s affairs.