单选题 Before the construction of the railroad, it was prohibitively expensive to transport any goods across the mountains.

【正确答案】 B

【答案解析】prohibitively(指价格等)高得买不起。四个选项：incredibly惊人地，异乎寻常地；determinedly决然地，断然地；forbiddingly冷酷地，令人生畏地；amazingly令人惊讶地，出奇地(通常作褒义)。