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。 小题1:Scientists are ________ (调查) into the cause of cancer. 小题2:To get the job done, one should be ________(精力充沛) and hardworking. 小题3:As a ______(奖赏)for passing her exams, she got a new bike from her parents. 小题4:Dilma Rousseff, who won 56% of the _______ (选票), was elected President of Brazil. 小题5:The old lady likes (spy) into other people’s affairs.