Q1. What is the passage mainly about?

1. AHow octopuses sleep and whether they might dream
2. BHow to catch an octopus
3. CWhy octopuses live in Okinawa
4. DHow octopuses eat fish

タコの2種類の眠りと、夢を見ているかという問いの話なので A。

Q2. How long does active sleep last?

1. AAbout ten seconds
2. BAbout one hour
3. CAbout one minute
4. DAbout seven hours

for about one minute とあるので C。

Q3. In this passage, "Nobody can say for sure" means ...

1. Aeveryone knows the answer
2. Boctopuses cannot talk
3. Cscientists are sure octopuses dream
4. Dno one knows the answer with certainty

for sure は「確かに」。誰も確かなことは言えない＝答えはまだわからない、なので D。

Q1. What is the passage mainly about?

1. AHow octopuses hunt at night
2. BResearch on octopus sleep stages and the question of dreaming
3. CWhy octopuses have eight arms
4. DHow humans dream during REM sleep

2つの睡眠段階の研究と、夢を見ているかという問いを扱っているので B。

Q2. What did the OIST team find?

1. AOctopuses never change color while sleeping.
2. BOctopuses sleep only once a day.
3. COctopuses can tell scientists about their dreams.
4. DSkin patterns in active sleep looked like waking patterns.

skin patterns during active sleep resembled patterns shown when awake とあるので D。

Q3. Why can't scientists confirm that octopuses dream?

1. ABecause octopuses cannot report what they experience
2. BBecause octopuses do not sleep
3. CBecause brain activity cannot be measured
4. DBecause the study used only humans

octopuses give no report of their experiences と理由が書かれているので A。

Q1. What is the passage mainly about?

1. AHow octopuses camouflage while hunting
2. BHow viral videos are made
3. CEvidence for two sleep stages in octopuses and why dreaming cannot be confirmed
4. DWhy octopuses need seven minutes of sleep

2段階の睡眠の証拠を示し、最後に夢は確認できない理由を述べているので C。

Q2. What evidence showed that active sleep is a real sleep state?

1. AThe animals were harder to wake, and the stage increased after sleep loss.
2. BThe octopuses' eyes stayed completely still.
3. CThe octopuses stopped breathing.
4. DThe octopuses turned completely white.

The animals were harder to wake during it, and they had more of it after sleep deprivation. とあるので A。

Q3. According to the author, why is it impossible to confirm that an octopus dreams?

1. ABecause octopuses have no brains
2. BBecause octopuses never sleep deeply
3. CBecause the equipment was too expensive
4. DBecause dreams can only be confirmed through verbal reports

Dreams are defined by subjective experience, which only a spoken report can confirm とあるので D。