转发一下800bob的解释: "That" is not only unnecessary, but wrong.
When a comparison includes "than that of" the word "that" refers to a specific noun. For example, in the following sentence:
The population of California is greater than that of New York.
..."that" stands in for "the population." The sentence can also be written:
The population of California is greater than the population of New York.
In choice C of the item under discussion:
wild animals have less total fat than that of livestock fed on grain
...what does "that" stand in for?
The problem with this item is that there is no good answer choice. What is the source? I'm sure it's not a real GMAT question.
The sentence should be something like this:
According to recent studies comparing the nutritional value of meat from wild animals and that of meat from domesticated animals, wild animals have less total fat than do livestock fed on grain and more fat of a kind thought to be good for cardiac health. C says: "wild animals have less total fat than that of livestock fed on grain." If "that" stands for "total fat" then the C means: "wild animals have less total fat than the total fat of livestock fed on grain." To me that makes no sense. The sentence is trying to compare wild animals with domesticated animals. It should read: "wild animals have less total fat than do livestock fed on grain."
There is no good answer. I suppose you could say that B is the "least bad," but settling for the "least bad" is never necessary on the GMAT. There's always a good sentence.
I wish I had stayed out of this discussion. I generally prefer not to comment on bogus questions. I will try one more time to explain why C is wrong, and then I promise to shut up. A comparison needs "than that of" or "than those of" only when it is comparing one possession or attribute to another possession or attribute. Generally the first item in the comparison will either be followed by a prepositional phrase beginning with "of" or be preceded by a possessive. Examples:
The total mass of all the asteroids is less than that of the Moon. ("That" refers to "mass," which is followed by "of.")
Shanghai's birth rate is lower than that of Western countries. ("That" refers to "birth rate," which is preceded by the possessive "Shanghai's.")
In choice C:
...wild animals have less total fat than that of livestock fed on grain...
"that," I suppose, is meant to refer to "total fat," but "total fat" is not followed by "of" or preceded by a possessive.
Try googling on "less total fat than" and you will get hundreds of hits, such as these:
Walkers Lites and Potato Heads contain 33% less total fat than Walkers crisps. "Reduced-fat" ice cream contains at least 25 percent less total fat than the regular product. Body mass indices did not demonstrate that men had less total fat than women. Peanuts actually have less total fat than most other nuts. Turkey has less total fat than other meats. Even the very fattest wild land mammals contain 60-75% less total fat than the average domesticated animal. In general, fish and poultry have less total fat than red meats. Grass-fed beef has a much better fatty acid ration and less total fat than grain-fed animals. Duck breast meat prepared without the skin (2 grams) has less total fat than chicken (3 grams) and more fat than turkey (0.5 grams). Wild deer meat has 44 percent less total fat than beef. KFC chicken had only slightly less total fat than a Whopper. The higher muscled-scored animal not only has more total meat but also has less total fat than the lower muscle-scored animal. Grass-finished meat has considerably less total fat than grain-fed animals. Chicken without skin has less saturated fat and less total fat than chicken with skin. Wild animals not only have less total fat than livestock fed on grain, but more of their fat is of a kind (omega-3) thought to be good for cardiac health.
(The last example, taken from a New York Times article, is obviously the source of the SC item under discussion here.)
Try googling on "less total fat than that of" and you will get not one single hit. |