单选题 As part of a delicately balanced system, the human heart secretes a hormone, a substance that controls the amount of salt in the blood and the volume of blood circulating within the body. Only very small quantities of the hormone are required. This hormone is extremely important in regulating blood pressure and is found in large amounts in the blood of those suffering a heart attack.
If the statements above are true, then it must also be true that

A、 if there is a deficiency in the amount of heart hormone secreted, low blood pressure will result.
B、 it is large quantities of the heart hormone that cause heart attacks to occur.
C、 the effects of a small amount of the heart hormone will be long-lasting in the body.
D、 if a device that is only a mechanical pump is used as an artificial heart, it will not perform all the functions of the human heart.
E、 (E) any drug that regulates blood pressure will have its effect by influencing the amount of the heart hormone secreted.

【正确答案】 D

【答案解析】[解析] 如果一个机械泵的装置被用作人工心脏，如(D)所说，那么它将不能分泌一种激素，因此就无法执行人体心脏的所有功能，所以(D)为正确答案；段落推理并未说明荷尔蒙少时会导致什么样的后果，因此(A)不对；段落最后一句只表明在患有心脏病的人的血液中有大量的荷尔蒙，但并没有说是由于荷尔蒙导致心脏病，所以(B)不对；(C)中的“long-lasting”是一个新概念，上文根本没有涉及，因此也不对。(E)中出现了上文中所没有出现的绝对化语言“any”，所以(E)也不对。另外，在归纳题中可首先看if、unless选项，这样我们可以将答案定位在选项(A)、(D)，再结合推理排除(A)，就可得出(D)为正确答案。