in the autumn和in autumn的指代不同，in the autumn是在一个特指的秋天，in autumn实在秋天。秋天有autumn和fall两种说法，只不过英国人一般把秋天叫作autumn，美国人则喜欢用fall。
In Great Britain, the third season of the year usually has only one name: autumn.
在英国，一年的第三个季节通常都只有一个名字：autumn。
The beginning of autumn doesn't mean the autumn has begun. Autumn starts when average temperature is below 22°C for 5 days in a row.
立秋不代表入秋，真正的秋天要根据“候平均温度”，当地连续5日的平均温度在22℃以下，才算真正进入秋天。
In his autumn years, he was able to enjoy his garden a lot more.
到了晚年，他可以在他的花园享受了。
I wants to spend his autumn years in Xiamen and go fishing everyday.
我想在厦门安度晚年，每天都去钓鱼。
