33 Thousands of Irish people starved during the "Potato Famine" because
A they were so dependent on potatoes that they refused to eat anything else.
B they were forced to leave their homeland and move to America.
C the weather conditions in Ireland were not suitable for growing potatoes.
D the potato harvest was bad.
34 Which country is the largest coffee producer?
A Brazil.
B Colombia.
C Ethiopia.
D Egypt.
35 Which of the following statements is NOT true, according to the passage?
A One third of the world's population drinks coffee.
B Coffee is native to Colombia.
C Coffee can keep one awake.
D Coffee drinks were first made by Arabs.
第二篇
Please Fasten Your Seatbelts
Severe turbulence (湍流) can kill aircraft passengers. Now, in test flights over the Rocky Mountains, NASA (美国航空航天局) engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it.
Clear-air turbulence often catches pilots by surprise. Invisible to radar, it is difficult to forecast and can hurl (用力抛出去) passengers about the cabin. In December 1997, one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds.
However, passengers can avoid serious injury by fastening their seatbelts. "It is the only antidote (对策) for this sort of thing," says Rod Bogue, project manager at NASA's Dryden Flight Research Center in Edwards, California.
The centre's new turbulence detector is based on lidar, or laser, radar. Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air. The technique depends on the Doppler Effect. The wavelength of the light shifts according to the speed at which the particles are approaching. In calm air, the speed equals the plane's airspeed. But as the particles swirl (打漩) in
