说明
in the evening/on the evening
核心问题
（1）What do you usually do ____? A. in an evening B. in the evening C. on the evening(全国高考)
(2) Surprisingly, the weather report on the evening before the storm said there would be strong winds, but not a hurricane.
试题(1)要求选 B(in the evening)，不能选 C(on the evening)，而句 (2) 却使用了 on the evening。这是怎么回事呢？
词典解答
in the evening 是笼统地指“晚上”，而 on the evening 是指某个特定的晚上。在句(2)中，the evening 后面有定语 before the storm，说明 the evening 是指一个特定的晚上，故必须用介词 on，而不能用介词 in。