用分面符号把类号分成若干段，使每段的号码代表主题的一个方面的制度是（）。
A.顺序标记制
B.混合标记制
C.分面标记制
D.层累标记制
参考答案：C
Which of the following statements best summarizes the main idea of the passage().
A. The British government risks missing its target of halting obesity in children under 11 by 2010.
B. It could be the first generation for decades to die before their parents because of obesity.
C. The British government’s efforts to tackle the problem of obesity are inefficient, confused and under-resourced.
D. The government has made some progress in dealing with the problem of obesity.
绿藻门的色素体形状有哪些种类，各是哪属的藻类？
