雅化集团：签署五年期锂辉石精矿采购协议

This pattern expresses a time limit or duration starting after a certain event happens. “在……后……内” means “within ... after ...” or “during the ... following ...”. In formal and business Chinese, it is often used to specify contractual periods.

“每” is used to show regular repetition over time, like “every year”, “every month”, or “per”. It is very common in both everyday and formal Chinese to describe repeated actions or fixed frequency.

These expressions are used to give quantity limits. “不少于” means “not less than / at least”, while “不超过” and “不超” mean “not more than / no more than”. They are especially common in contracts, notices, and financial writing.

“因” is a formal way to say “because of”. The structure “因……需要” means “due to the need for ...”. It is often used in written, official, or business Chinese to explain the reason for an action or plan.

“通过” introduces the method, channel, or means used to do something. It often corresponds to “through”, “by”, or “by means of” in English. In formal texts, it frequently appears with transaction methods or procedures.