關於TPO 13 - 英檢

我想請問TPO 13

biological clock

這題的答案是不是有點怪怪的@@?
(我是網路上面下載來的黃金5.9)

插入題和最後一題
完全解不出來

有人可以回答我嗎@@...

Paragraph 3：Animals need natural periodic signals like sunrise to maintain a
cycle whose period is precisely 24 hours. ■Such an external cue not only
coordinates an animal's daily rhythms with particular features of the local
solar day but also—because it normally does so day after day-seems to keep
the internal clock's period close to that of Earth's rotation. ■Yet despite
this synchronization of the period of the internal cycle, the animal's timer itself continues to have its
own genetically built-in period close to, but different from, 24 hours. ■
Without the external cue, the difference accumulates and so the internally
regulated activities of the biological day drift continuously, like the
tides, in relation to the solar day. ■This drift has been studied
extensively in many animals and in biological activities ranging from the
hatching of fruit fly eggs to wheel running by squirrels. Light has a
predominating influence in setting the clock. Even a fifteen-minute burst of
light in otherwise sustained darkness can reset an animal's circadian rhythm.
Normally, internal rhythms are kept in step by regular environmental cycles.
For instance, if a homing pigeon is to navigate with its Sun compass, its
clock must be properly set by cues provided by the daylight/darkness cycle.


Because the internal signals that regulate waking and going to sleep tend to
align themselves with these external cues, the external clock appears to
dominate the internal clock.


最後一題我選了

1.Most animals survive and reproduce successfully without coordinating their
activities to external environmental rhythms.

2.The circadian period of an animal's internal clock is genetically determined
and basically unchangeable.

3.Because an animal's internal clock does not operate on a 24-hour cycle,
environmental stimuli are needed to keep the biological day aligned with the
solar day.

可以告訴我正確的答案嗎拜託~

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