The story begins more than 50 years ago中begin为什么要加s

问题描述:

The story begins more than 50 years ago中begin为什么要加s
不是过去式吗为什么不是began?
整个句子是这样的The story begins more than 50 years ago,when I was seven years old and we lived in a big house

表示客观事实,故事发生在50年前,用一般现在时