六 完形填空

1、 12题目Smoking Can Increase Depressive

Symptoms in Teens；文章

While some teenagers may puff on cigarettes to “self-medicate” against the blues,scientists at the University of Toronto and the University of Montreal have found that smoking may actually increase depressive symptoms in some teens.

“This observational study is one of the few to examine the perceived emotional benefits of smoking among teens,”says lead researcher Michael Chaiton,a research associate at the Ontario Tobacco Research Unit of the University of Toronto.“Although cigarettes may appear to have self-medicating effects or to improve mood,in the long term we found that teens who started to smoke reported higher depressive symptoms.

As part of the study,some 662 high school teenagers completed up to 20 questionnaires about their use of cigarettes to affect mood.Secondary schools were selected to provide a mix of French and English participants,urban and rural schools,and schools located in high,moderate and low socioeconomic neighbourhoods.

Participants were divided into three groups :never smokers;smokers who did not use cigarettes to self-medicate,improve mood or physical state ;smokers who used cigarettes to self-medicate.Depressive symptoms were measured using a scale that asked how often participants felf too tired to do things;had trouble going to sleep or staying awake ;felt unhappy,sad,or depressed;felt hopeless about the future;felt vexed,antsy or tense;and worried too much about things.

“Smokers who used cigarettes as mood improvers had higher risks of elevated depressive symptoms than teens who had never smoked,”says co-researcher Jennifer O’Loughlin,a professor at the University of Montreal Department of Social and Preventive Medicine. “Our study found that teen smokers who reported emotional benefits from smoking are at higher risk of developing depressive symptoms.”

The association between depression and smoking exists principally among teens that use cigarettes to feel better. “It’s important to emphasize that depressive symptom scores were higher among teenagers who reported emotional benefits from smoking after they began to smoke,”says Dr.Chaiton. 二、 11题目 China to Help Europe Develop GPS Rival

China is to contribute to a new global satellite navigation system being developed by European nations.The

Galileo satellite system will offer a more accurate civilian alternative to the Global Positioning System (GPS), operated by the US military. China will provide 230m Euros (USD 259m) in funding and will cooperate with technical, manufacturing and market development. “China will help Galileo to become the major world infrastructure for the growing market for location services,” said Loyola de Palacio, EU transport commissioner. A new center that will coordinate co-operation was also announced by the European Commission, the European Space Agency (ESA) and the Chinese Ministry of Science and Technology not long ago . The China-Europe Global Naigation Satellite System Technical Training and Cooperation Center will be located at Beijing University. China has a substantial satellite launch industry and could potentially help launch the Galileo satellites.

The US has claimed that Galileo could interfere with the US ability to downgrade the Gps service during military conflicts. European officials say this is unfounded and counter that US opposition is due to the commercial challenge Galileo would present to GPS.Galieo will be precise to within a meter, while the civilian GPS service is accurate to around 10 meters.

The Galileo satellite constellation will consist of 27 operational and three reserve satellites orbiting the Earth at an altitude of 23,600 km. The satellites will be strung along three medium-Earth orbits at 56 degrees inclination to the equator and will provide global coverage . The system should be operational by 2008 and the entire project is expected to cost around 3.2 billion Euros (USD 3.6 billion).

The European Commission has said Glileo will primarily be used for transportation technology, scientific research, land management and disaster monitoring.

Galileo will provide two signals: a standard civilian one and an encrypted, wide-band signal called the Public Regulated Service (PRS). This second signal is designed to withstand localized jamming and will be used by police and military services in Europe. European Commission officials have said China will not be given access to the PRS.

The first Galileo satellite is scheduled to launch late in 2004. Clocks on board the satellite will be synchronized through 20 ground sensors stations, two command centers and 15 uplink stations.

Receivers on the ground will use time signals from the satellites to precisely calculate their location . A “search and rescue” function will also let distress signals be relayed through the constellation of satellites.