阅读下面短文， 从每小题所给的 A、B、C、D四个选项中选出最佳选项
Cici is standing a few steps ahead - her- trainer. Her trainer says," Right." Cici makes a 90- degree turn." Forward." Cici walks toward the、 sidewalk and starts to walk down it. Cici is training to be a guide dog. Guide dogs help people who are blind or disabled.
But, how do trainers make sure their dogs are right for the work? Jim Alloway is a leader of Pilot- Dogs in Columbus. Before starting to train the puppies(小狗), he and his team test qualities that trainers can't teach. In one test, trainers drop a box on the floor near the puppies. Do they ignore(忽视) the noise? Do they run away? Do they jump, and then look around? Puppies that ignore the noise or run away are not considered good choices. Other tests answer questions like: Is the dog confident? Is the dog safe for their owners? Is the dog happy as a guide dog? More than half of all dogs tested fail. They end up doing some other service work or become family pets.
Once a puppy passes the tests, trainers begin teaching the dog basic commands(命令) like" come" and" sit". It is not easy. Puppies are still babies. They don't always follow the rules. It takes months of patient practice to teach a puppy to obey a command. Trainers usually motivate dogs in a positive way. When the dog does something correctly, it gets a treat(奖励).
As the puppies get older, they practice in an indoor facility that has stairs to climb and obstacles(障碍) to go around. After that, trainers add distractions(干扰). They throw toys and make loud noises. This trains the dogs to notice the distractions, and then ignore them if they are not dangerous.
After practicing inside, trainers take the dogs outside. They learn how to cross streets safely and how to get onto buses. They learn to keep away from common dangers, like steps on the ground, and running cars.
It can take up to two years for a puppy to become a guide dog. But once it starts to work, it will be the best helpers for its human partners.
