tpo15-a warm-blooded turtle - 英檢

Paragraph 6:【 In a countercurrent exchange system , the blood vessels carrying
cooled blood from the flippers run close enough to the blood vessels carrying
warm blood from the body to pick up some heat from the warmer blood vessels;
thus, the heat is transferred from the outgoing to the ingoing vessels before
it reaches the flipper itself】. This is the same arrangement found in an
old-fashioned steam radiator, in which the coiled pipes pass heat back and
forth as water courses through them . The leatherback is certainly not the only
animal with such an arrangement; gulls have a countercurrent exchange in their
legs. That is why a gull can stand on an ice floe without freezing.

8.Which of the sentences below best expresses the essential information in the
[ highlighted sentence ] in the passage?

。In a turtle's countercurrent exchange system, outgoing vessels lie near
enough to ingoing ones that heat can be exchanged from the former to the latter
before reaching the turtle' s flippers.

。Within the turtle' s flippers, there is a countercurrent exchange system that
allows colder blood vessels to absorb heat from nearby warmer blood vessels and
then return warmed blood to the turtle's body.


我選的是第二個選項,但是答案是第一個,我搞不太懂這兩個選項的差異

請問如何推敲出答案是第一個呢??謝謝!!!

--