翻译英语语段：Researchers from the University of Iowa based...

1.Researchers from the University of Iowa based their findings on a review of 18 earlier studies that looked at the association between sunscreen use and melanoma.They said that they found flaws in studies that had reported associations between sunscreen use and higher risk of melanoma.
2.But questions have been raised about sunscreen and whether it may have the opposite effect,perhaps by allowing people to remain exposed to the sun longer without burning.
3.The studies,which generally relied on wolunteers to recall their sunscreen use,were also unable to prove how well the products had been applied,said the new study.

1.Researchers from the University of Iowa based their findings on a review of 18 earlier studies that looked at the association between sunscreen use and melanoma.They said that they found flaws in studies that had reported associations between sunscreen use and higher risk of melanoma.来自爱荷华州大学的研究者把他们的研究成果建立在先前的18个对于防晒霜和黑色素瘤两者联系的研究的一个回顾检验之上。他们声称他们发现了这些研究的瑕疵，这些研究报告指出了防晒霜的使用和黑色素瘤的更高风险之间的联系
2.But questions have been raised about sunscreen and whether it may have the opposite effect,perhaps by allowing people to remain exposed to the sun longer without burning.但是由此产生了关于防晒霜的疑问以及防晒霜是否会通过让人更久的暴露烈日下而产生相反效果。
3.The studies,which generally relied on wolunteers to recall their sunscreen use,were also unable to prove how well the products had been applied,said the new study. 新的研究中指出，主要依靠志愿者对于他们使用防晒霜的回忆而做的这些研究也不能证明这些防晒产品是否被正确涂抹使用。

研究员爱荷华大学的调查结果为基础进行审查研究， 18日早些时候望着之间的联系防晒霜使用和melanoma.他们说，他们发现缺陷的研究报告说，协会之间的防晒使用和风险较高的黑色素瘤。

但是，问题已经提出了防晒霜和是否有可能产生相反的效果，也许可以让人们保持暴晒不再没有燃烧。