Question

For many years, ____ animals for carrying food and other supplies from one area to another has been a means of living in Xinjiang Autonomous Region .

A．trained

B．training

C．having trained

D．to have trained

Answer 1

B

試題分析：考查動名詞作主語。本題的主語是動名詞短語training animals for carrying food and other supplies from one area to another.謂語動詞用單數(shù)形式。故B正確。C項是完成式，表示已經(jīng)完成的動作，與句意不符。
點評：動名詞做主語指經(jīng)常性，習(xí)慣性的行為。單個的動名詞做主語的時候，謂語動詞用單數(shù)。