第21题: [单项选择]肝巨噬细胞位于下列哪种结构?() A. 肝细胞索中 B. 门管区内 C. 胆小管中 D. 肝血窦中 E. 窦周隙内 参考答案:D
第22题: [单项选择]Questions 22-25 are based on the following passage.What is in great demand in factories A. Diamonds. B. Diamond dust. C. Big diamond stones. D. Hard steel. 参考答案:B 答案解析:本题的关键词句为it is not the big stones needed for the drills,和demand the diamond dust…由关键词可推断出答案。