Dec 2009;3/16

lily88888UID: 2828533

16. A conunon genetic mutation that lowers levels of the enzyme cathepsin C severely reduces a person's ability to ward off periodontitis, or gum disease, The enzyme triggcrs immunological reactions that destroy diseased cells and eliminate infections in the mouth. But researchers are developing ways to restore the enzyme to nomlal levels. Once that happens, we will be able to climinate periodontitis.

Which one of the following is an assumption on which the argument depends?
(A) Restoring cathepsin C to nomlal levels is the only way to eliminate periodontitis.
(B) Genetic mutation is the only cause of lowered levels of cathepsin C.
(C) Researchers will soon succecd in finding means of restoring cathepsin C to nonnal levels.
(D) Persons who do not have the genetic mutation that lowers levels of cathcpsin C do not get gum disease.
(E) A person whose cathepsin C level has been restored to nomlal will not suffer from periodontitis.

duijinxiaoziUID: 2585955

题干：
But researchers are developing ways to restore the enzyme to nomlal levels. Once that happens, we will be able to eliminate periodontitis.
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（E）是上句的同义改写。