What can we learn from Para 3 & 4?

参考解析：

细节理解题。根据文章第三段第一、二句“Generally, the first afternoon teas were very small meals indeed. The meal rarely contained meat or alcohol”可知，一般来说，第一次下午茶的确是很少量的食物。这顿饭很少含有肉或酒精，因此A项错误；根据文章第四段最后一句“Women are mainly the ones in attendance, though formal afternoon teas may also include some men”可知，出席下午茶的主要是女性，不过正式的下午茶也可能包括一些男性，因此B项正确；根据文章第四段第一句“Today’s afternoon teas are often as large and filling as a full meal, occasionally replacing dinner”可知，下午茶偶尔可以取代晚餐，C项中的“已经取代晚餐”错误；根据文章第三段最后一句“In the lower classes, these meals were filling but simple”可知，在下层社会，这些食物很饱，但很简单，因此D项中的higher应该改成lower。故选B。