在制作口腔上皮细胞临时装片时，将标本放在0.9%的生理盐水中，是为了[ ]
A．保持细胞原形态
B．保持标本透明度
C．容易染色
D．防止标本干燥
答案：A
I always ___________ my grandparents.[ ]
A. visit
B. visits
C. visiting
D. visited
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.
