食物链可分为捕食食物链、腐屑食物链、______和混合食物链。
参考答案：寄生食物链
A financial analyst could correct the current ratio in which a company uses the LIFO inventory valuation method to the FIFO method by:（）
A. adding the LIFO reserve to the current liabilities.
B. adding the LIFO reserve to the current assets.
C. deducting the LIFO reserve from the current asset.
患者，男性，19岁，头晕乏力3个月，Hb58g／L，WBC3．8×109／L，血小板50×109／L，胸骨穿刺有核细胞增生活跃，各系细胞形成正常，需再做哪项检查（）
A.髂骨穿刺
B.脊髓穿刺
C.复查血常规
D.骨髓染色
E.红细胞铁染色
