What are the breeds of guide dogs?

There have been several movies before where guide dogs have appeared, there is a Hong Kong movie dedicated to the training of guide dogs, the staff of the training camp is very dedicated to pairing people and dogs. There is a period of adaptation, two-way choice is not suitable to change, and later there is a visit, for people and dogs are responsible. There are actually many breeds, the main one being intelligent, loyal and responsible, with Labradors, Golden Retrievers and German Shepherds being the most common.