かき氷の「キーン！」には正式な医学名があった。頭が痛くなる仕組みと、すぐ消える理由

Q1. What is the passage mainly about?

1. AWhat brain freeze is and how to avoid it
2. BWhy shaved ice is popular in summer
3. CHow to make ice cream at home
4. DWhy children like cold food

ブレインフリーズの正体と、ゆっくり食べると防げることが書かれているので A。

Q2. Where does the cold touch?

1. AThe forehead
2. BThe ears
3. CThe back of the mouth
4. DThe stomach

The cold touches the back of your mouth とあるので C。おでこは「痛む場所」なので注意。

Q3. In this passage, "goes away" means ...

1. Agets worse
2. Bstarts
3. Cmoves to the back
4. Dstops

go away は「去る・消える」。痛みが1分もしないうちに消える＝止まる、なので D。

Q1. What is the passage mainly about?

1. AThe history of ice cream in Canada
2. BThe causes of brain freeze and a way to prevent it
3. CWhy the trigeminal nerve is dangerous
4. DHow headaches are classified around the world

関連痛と血管という2つの原因と、ゆっくり食べるという予防法が書かれているので B。

Q2. In the Canadian experiment, which group got brain freeze less often?

1. AStudents who ate ice cream within five seconds
2. BStudents who drank hot tea first
3. CStudents who ate slowly over 30 seconds or more
4. DStudents who did not eat anything

students who ate ice cream slowly, taking 30 seconds or more, were less likely to get brain freeze とあるので C。

Q3. Why might the brain "misread" where the cold signal came from?

1. ABecause the same nerve carries signals from the mouth and the face
2. BBecause the forehead is colder than the mouth
3. CBecause blood stops flowing to the brain
4. DBecause ice cream contains a lot of sugar

The trigeminal nerve carries signals from both the mouth and the face, so ... とあり、同じ神経が両方を担当しているのが理由なので A。

Q1. What is unusual about the pain of brain freeze?

1. AIt only occurs in children.
2. BIt lasts for several hours.
3. CIt is not recognized by doctors.
4. DThe pain appears in a different place from where the cold is applied.

the cold hits the palate and throat, yet the pain shows up in the forehead or temples とあるので D。冷えた場所と痛む場所がちがう。

Q2. What did Hensel and colleagues find?

1. AAll 77 participants developed a headache.
2. BBlood flow velocity fell in people with headaches.
3. CPeople with headaches showed a greater rise in blood flow velocity.
4. DIce water caused no change in blood flow.

The 39 who developed a headache showed a greater rise in blood flow velocity とあるので C。頭痛が出たのは77人中39人。

Q3. What weakness of the 2002 trial does the author mention?

1. AIt relied on students reporting their own pain.
2. BIt was published only as a joke.
3. CThe students ate different flavors of ice cream.
4. DIt contradicted the Hensel study.

a modest 2002 randomized trial in Canada that relied on students reporting their own pain とあるので A。自己申告は研究の限界の典型。