According to two teams of paleontologists, recent fossil discoveries in Pakistan show that whales, porpoises, and dolphins are more closely related to some of the oldest known even-toed ungulates--a group of hoofed mammals that today includes cows, camels, pigs, and hippos--than to any other mammals.
(A) that whales, porpoises, and dolphins are more closely related to some of the oldest known even-toed ungulates--a group of hoofed mammals that today includes cows, camels, pigs, and hippos--than
(B) that whales, porpoises, and dolphins are more closely related to some of the oldest known even-toed ungulates--a group of hoofed mammals that today include cows, camels, pigs, and hippos--as
(C) whales, porpoises, and dolphins to be more closely related to some of the oldest known even-toed ungulates--a group of hoofed mammals that today include cows, camels, pigs, and hippos--than they are
(D) whales, porpoises, and dolphins as being more closely related to some of the oldest known even-toed ungulates--a group of hoofed mammals that today includes cows, camels, pigs, and hippos--as they are
(E) whales, porpoises, and dolphins as more closely related to some of the oldest known even-toed ungulates--a group of hoofed mammals that today include cows, camels, pigs, and hippos--than
(A) 正确，that引导宾语从句，比较结构为more closely related to … than to…。
(B) more…as… 搭配错误，应该是more… than…。
(C) 宾语从句缺少引导词that； show sth to be… 变宾语从句为名词+修饰词结构错误；they are在这种没有歧义存在的情况下可以省略，使句子更简洁。
(D) 宾语从句缺少引导词that；more…as… 搭配错误，应该是more… than…；show sth as being… 表达方式错误；they are在这种没有歧义存在的情况下可以省略，使句子更简洁。
(E) 宾语从句缺少引导词that；show sth as…表达方式错误。
想问一下 是因为画线部分后的to消除了歧异吗??
谢谢各位NN~ | 
