A. Have you got an email from Tom?
B. What did your mother have for lunch?
C. Does Lingling like hamburgers?
D. He says sandwiches are delicious.
E. I had eggs and milk.
有的微生物能够分解枯枝落叶、动物的遗体和粪便中的有机物，从而获得生活必需的物质和能量，这样的营养方式称为____。这类微生物是生态系统成分中的____者。
