(2) the trademark of the other party can be revoked by providing proof of using the "Tianyuan" trademark

(3) the other party's trademark cannot be used before it is revoked, and others cannot be prohibited from using it

(4) it should be understood that the trademark should be registered before it is used, and 8) it can help solve a case analysis topic of intellectual property law. A Meihua Dairy Factory in a certain city uses the trademark "Tianyuan" on a series of products it produces. The products produced by this factory are of good quality and are deeply loved by consumers. They have been rated as "products trusted by consumers" for three consecutive years. In January, 24, No.3 Food Factory applied for trademark registration of Tianyuan, which was used on the dairy products it produced after approval, and requested Meihua Factory to stop using the trademark, otherwise, it would be accused of trademark infringement. Q:

(1) Is it legal for the Third Food Factory to obtain the trademark right and why?

(2) In what ways can Meihua Dairy Factory protect its interests from damage? What are the reasons?

(3) Can Meihua Factory continue to use the "Tianyuan" trademark and prohibit others from using it?

(4) What lessons should Meihua Dairy Factory learn from this incident?