C)Sweet corn D) Chocolate beans 20. A)They led to the discovery of America. B)They made native American foods popular C)They brought great wealth to spain. D)They made native American life styles well-known Part II Reading Comprehension (35 minutes) Directions There are 4 passages in this part. Each passage is followed by some questions or unfinished atements. For each of them there are four choices marked A), B), C)and D). You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the centre. Questions 21 to 25 are based on the following passage The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in business class. In the last 15 years, pilots have reported well over 100 incidents that could have been caused by electromagnetic interference. The source of this interference remains unconfirmed but increasingly, experts are pointing the blame at portable ele devices such as portable computers, radio and cassette players and mobile telephones. TCA, an organization which advises the aviation (BE)industry, has recommended that all airlines ban(1E) such devices from being used during"critical" stages of flight, particularly take-off and landing. Some experts have gone further calling for a total ban during all flights Currently, rules on using these devices are left up to individual airlines. And al though some airlines prohibit passengers from using such equipment during take-off and landing, most are reluctant to enforce a total ban, given that many passengers want to work during flights. The difficulty is predicting how electromagnetic fields might affect an aircraft s s. Experts know that portable devices emit radiation which affec ts those wavelengths which aircraft use for navigation and communication because they have not these effects in a laboratory, they have no way of knowing whether the interference might be dangerous or not The fact that aircraft may be vulnerable(易受损的) to interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As worrying, though is the passenger who can t hear the instructions to turn off his radio because the musics too loud 21. The passage is mainly about A)a new regulation for all airlines b) the defects of electronic devicesC) Sweet corn. D) Chocolate beans. 20. A) They led to the discovery of America. B) They made native American foods popular. C) They brought great wealth to Spain. D) They made native American life styles well-known. Part II Reading Comprehension (35 minutes) Directions: There are 4 passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the centre. Questions 21 to 25 are based on the following passage: The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in business class. In the last 15 years, pilots have reported well over 100 incidents that could have been caused by electromagnetic interference. The source of this interference remains unconfirmed, but increasingly, experts are pointing the blame at portable electronic devices such as portable computers, radio and cassette players and mobile telephones. RTCA, an organization which advises the aviation (航空) industry, has recommended that all airlines ban (禁止) such devices from being used during "critical" stages of flight, particularly take-off and landing. Some experts have gone further, calling for a total ban during all flights. Currently, rules on using these devices are left up to individual airlines. And although some airlines prohibit passengers from using such equipment during take-off and landing, most are reluctant to enforce a total ban, given that many passengers want to work during flights. The difficulty is predicting how electromagnetic fields might affect an aircraft's computers. Experts know that portable devices emit radiation which affects those wavelengths which aircraft use for navigation and communication. But, because they have not been able to reproduce these effects in a laboratory, they have no way of knowing whether the interference might be dangerous or not. The fact that aircraft may be vulnerable (易受损的) to interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As worrying, though, is the passenger who can't hear the instructions to turn off his radio because the music's too loud. 21. The passage is mainly about ________. A) a new regulation for all airlines B) the defects of electronic devices