The question of whether to divest themselves of stock in companies that do business in South Africa is particularly troublesome for the nation's 116 private Black colleges because their economic bases are often more fragile than most predominantly White colleges.
OG1181l8. The question of whether to divest themselves of stock in companies that do business in South Africa is particularly troublesome for the nation’s 116 private Black colleges because their economic bases are often more fragile than most predominantly White colleges.
比较的两个事物应该合理,且省略的时候要以不产生歧异为标准, 如果不加those of,则是black colleges's economic bases 与 white colleges比较,即 base 与 colleges 比较,意思上不合理,只能是base与base比较,所以加上了thoes of代指base of