An Indian anthropologist, Chandra Thapar,

问题：

An Indian anthropologist, Chandra Thapar, made a study of foreign cultures, which had customs similar to (91) of his native land. One culture in (92) fascinated him because it reveres one animal (93) sacred, much as the people in India (94) the cow. The things he discovered might interest you (95) you will be studying India as part of this course.
The tribe Dr. Thapar (96) is called the Asu and is found on the American continent north of the Tamhumara of Mexico. Though it seems to be a (97) developed society of its type, it has an overwhelming (98) with the care and feeding of the rac—an animal much like a bull in size, strength and temperament. In the Asu tribe, it is almost a social (99) to own at least one (100) not more rats. People not possessing at least one are (101) in low esteem by the community because they are too poor to (102) one of these beasts properly. Some members of the tribe, to (103) their wealth and social prestige, even own (104) of racs.
(105) the rac breed is not very healthy and usually does not live more than five to seven years. Each family invests large (106) of money each year to keep its rac healthy and shod, for it has a tendency to throw its shoes often. There are rac (107) in each community, perhaps more than one if the community is particularly (108) . These specialists, however, due to the long period of ritual training they must undergo and (109) the difficulty of obtaining the right selection of charms to treat the rac, demand (110) offerings whenever a family must treat an ailing rac.

A．as

B．if

C．with

D．when