⑴____ A. few   B. new  C. knew  D. sew

⑵____ A. house  B. south C. soul   D. mouth

⑶____ A. wall   B. shall   C. fall  D. call

⑷____ A. none   B. chose  C. note  D. close

⑸____ A. grown  B. known  C. thrown D. town

— What colour is it?   

— It's ____.

大多数细菌只能利用现成的有机物生活，是生态系统中的分解者．