在特异性免疫中发挥作用的主要细胞是[ ]
A.红细胞
B.吞噬细胞
C.淋巴细胞
D.血小板
答案:C
漏磁场与缺陷深度有何关系?
Passage One
Which of the following statements is NOT true of the global tourism industry a. The tourism industry is undergoing restructuring in parts of the world. b. It remains thoroughly fragmented and widely distributed. c. It yields considerable annual profits. d. It creates more than 200 million jobs globally.