练习第一段

According to the information of beef and lamb, which both had a decreasing trend, it declined gradually despite of slight fluctuations. The former changed from the maximum point at about 220 grams in 1979 to the least figure of 110 grams in 2004 (descent by nearly 50%), the latter dropped from 150 grams to 55 grams at the same period. The data indicated that the beef popularity has dropped into the second preferred one, while the preference of lamb was fallen either by the public.