【单选题】第一篇 Immune Functions The immune system is equal incomplexity to the combined intricacies of the brain and nervous system. Thesuccess of the immune system in defending the body relies on a dynamicregul...
【单选题】AIDS (Acquired Immune Deficiency Syndrome) is a fatal disease that destroys the immune system. More than four out of five AIDS cases in the United States so far have been homosexual or bisexual men or...