四川省2020高考英语一轮复习题型整合练5含解析5.pdfVIP

四川 2020 高考英语一轮题型整合练（5） 一、阅读理解。 A (2018·广西重点高中模拟)People love cellphones, which is why nine in ten Americans own one.But does heavy use of cellphones pose a risk of cancer? This question has caused controversy for many years. A new study in rats now augments those concerns.Its data linked longterm, intense exposure to radiation from cellphones with an increased risk ofcancer in the heart or brain.Theresults have yet to be confirmed, the authors note. Indeed, although the rat study found a link between cellphone radiation an cancer, it offers no clues to why such a link might exist, notes Jonathan Samet.He teaches preventative medicine and directs the Institute for Global Health at the University of Southern California in Los Angeles.Still, he calls the new study’ s findings significant”．They could lead to studies researching how cellphone radiation might cause cancer, he says. Phone signals are relayed between cell towers and cellphones via radio waves.This radio frequency—or RF—radiation is a type known as non ionizing(非 电离的). Unlike X rays, non ionizing radiation does not deposit enough energy into cells to release electrons from atoms or molecules, producing ions.So it tends to be far less harmful than ionizing radiation,such as X rays.But that does not mean radio waves might not cause harm. In very large doses(量) this radiation will heat the body and cause tissue damage.But it’s not yet known what much lower RF levels might do, such as those from cellphone use.Five years ago, the World Health Organization’s International Agency for Research on Cancer, or IARC, conclude that cellphone use is possibly carcinogenic(致癌的)”． Its conclusion was based on what little research data was available at that time.But notice that IARC was not certain.It said only that phone use might “possibly”cause cancer.So scientists at the National Toxicolog Program, or NTP, investigated further. 【解题导语】 本文是一篇说明文。