完成句子根据汉语意思完成下列句子，每空一词 (共20个空格；每空0.5分，满分10分)
这种药物已经进行过人体试验；现在有一点是肯定的，它有可能降低得心脏病的风险。
The drug has been _____ _____ on humans. _____ is certain now is that it has the _____ to reduce the risk of heart attacks.
人们建造动物园是为了拉近人类社会和大自然的距离。而且，动物园能为当地的旅游业做贡献，这肯定是对周围地区的经济发展有利的。
Zoos are built to shorten the distance between human society and nature. _____ _____, zoos can _____ _____ local tourism, which is surely _____ _____ the economic development of the local neighborhoods.
为了找出那起事故的真相，他一直在当年的报刊杂志中仔细搜寻，另外还查阅了所有相关的网页。
In order to find out the truth of the accident, he has been _____ _____ all the newspapers and magazines of that year, along with all the relevant web pages.
研究显示有些将过多时间用于上网的学生已经辍学，他们往往会脱离周围的人和世界。
The study shows that some students, who spend too much time on the Internet, have _____ _____ and tend to _____ _____ the people and the world around them.
在完成了一项为期三个月的工程后，她累坏了；为了放松一下，她已决定今年去法国度假。
She was _____ _____ after a three-month-long project and has _____ _____ France for her holiday this year for relaxation.