It was unusually hot last summer in Britain.

　　题干大意：去年夏天，英国不同寻常的热。该题的关键词为"unusually hot"和"last summer"，定位到文中第二段第一句"Last summer though, it was so hot that people could hardly believe it."然而去年夏天，天气热到让人难以置信，也就是题干所说的不同寻常的热。该题为细节理解题，题干意思与原文相符，故选A。