______ the growing fears about home security, more people are arranging for someone to stay in their home when they’re away.

cancer. originally,because of a lawsuit that alleged such a link Network news programs ran their own tests of cell phones,reporting to the public that some cell phones exceed the maximum level of emitted radio frequency energy allowed by the US Federal Communications Commission.

In 2000.it was estimated that there were 92 million cell phone users in the United States and this number was growing by 1 million every month. More recently,the Cellar Telecommunications & Internet Association estimated that there were almost 170 million US cell phone users, and the seriousness of brain tumours, this is clearly a topic of wide concern.This report summarizes what we now know about the carcinogenicity of using cell phones.

Cell phones operate with radio frequencies.a form. of energy located on the electromagnetic spectrum between F M radio waves and the waves used in microwave ovens,radar;and satellite stations.Cell phones do not emit ionizing radiation,the type that damages DNA and is known to have the ability to cause cancer.

Cell phone technology works on a system of geographically separated zones called "cells" Each cell has its own "base station" that both receives and emits radio waves.When a call is placed from a cell phone,a signal is sent from the cell phone antenna to that cell's base station antenna.The base station responds to the cell phone signal by assigning the phone an available RF channel.When the RF channel is assigned,radio signals are simultaneously received and transmitted, allowing voice information to be carried between the cell phone and the base.The base station transfers the call to a switching centre.where the call can be transferred to a local telephone carrier or another cell phone.

6.There has existed argument about the link between cell phone and brain tumour.()

7.The rapid growing number of cell phone users has been a great concern in the US.()

8.The 3rd paragraph tries to prove that cell phones do not cause brain cancer.()

9.A switching centre is needed when we make a call through cell phone.()

10.The topic of the passage is about cell phone and cancer.()

Part III Reading Comprehension (40 minutes)2016年6月大学英语四级卷1真题及答案

Section A

Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once.

Questions 26 to 35 are based on the passage you have just heard.

Physical activity does the body good, and there's growing evidence that it helps the brain too. Researchers in the Netherlands report that children who get more exercise, whether at school or on their own,26to have higher GPAs and better scores on standardized tests. In a27of 14 studies that looked at physical activity and academic28, investigators found that the more children moved, the better their grades were in school,29in the basic subjects of math, English and reading.

The data will certainly fuel the ongoing debate over whether physical education classes should be cut as schools struggle to30on smaller budgets. The arguments against physical education have included concerns that gym time may be taking away from study time. With standardized test scores in the U.S.31in recent years, some administrators believe students need to spend more time in the classroom instead of on the playground. But as these findings show, exercise and academics may not be32exclusive. Physical activity can improve blood33to the brain, fueling memory, attention and creativity, which are34to learning. And exercise releases hormones that can improve35and relieve stress, which can also help learning. So while it may seem as if kids are just exercising their bodies when they're running around, they may actually be exercising their brains as well.

A)attendance

B)consequently

C)current

D)depressing

E)dropping

F)essential

G)feasible

H)flow

I)mood

J)mutually

K)particularly

L)performance

M)review

N)survive

O)tend

This year, the number of club members__________very quickly.

A. is growing

B. grows

C. are growing

D.growing

A.on

B.in

C.at

D.above

There is a growing ()ABout the effects of pollution on health.

A、problem

B、counseling

C、concern

D、debate

His cold was growing ________

A.harder

B.worse

C.heavier

D.seriously

A.growing

B.grows

C.grew

D.grown