This is the 5198th most frequent Chinese word.
一来
"一来" means "for one thing" or "on one hand."
"一来" is used to introduce the first reason or aspect in a sequence of reasons or aspects.
一来我们认识多年，二来他人品很好，所以我推荐他。
Firstly, we have known each other for years; secondly, he has great character, so I recommended him.
"一来" in repetition emphasizes parallel aspects rather than sequential order.
一来天气凉爽，一来风景怡人，这个地方很适合度假。
First, the weather is pleasant; first, the scenery is lovely; this place is ideal for a vacation.
"一来" presents the first point in a context of reasoning or explanation.