Rare species in the world, ______ by hundreds every year, must be jointly preser

题型：不详难度：来源：

Rare species in the world, ______ by hundreds every year, must be jointly preserved by all countries, or humans will encounter ecological disaster in the near future.

答案

A. disappeared     B. disappearing     C. disappear        D.having disappearedB

解析

试题分析：考查现在分词作状语。disappearing by hundreds every year做原因状语，disappearing的逻辑主语是Rare species，句意是在世界上，每年有上百种的珍稀动物消失，所以所有的国家必须联合起来保护它们，否则在不久的将来人们将遭遇生态上的灾难。Disappeared过去分词，表示已经完成的动作；having disappeared现在分词的完成式，表示谓语动词动作之前已经完成的动作；disappear动词作谓语，题***谓语是must be，现在分词表示正在进行的动作，根据句意选B。
点评：现在分词的构成是动词原形加ing，被动语态是being done，完成式是having done，having been done。在句中可做表语，状语，定语，补语等。