第二节 语法填空(共10小题;每小题1.5分，满分15分)
阅读下面材料，在空白处填入适当的内容或括号内单词的正确形式。
Air travel makes both people and service dogs very nervous. There are classes that help people defeat their fear of flying. And there is similar training for service dogs 41_______ (suffer) the same problem. You will see 42_______ working on buses, trains and other public transport systems. But the busy environment found at an airport can trouble even the best 43_______ (train) service dogs. People with disabilities depend 44_______ their dogs to safely guide them through security areas. They need the dogs to remain calm on duty on the airplane, especially 45_______ the flying is not smooth. It takes special training.
The Air Hollywood K9 Flight Center is a school 46_______ such help can be found. Dog trainers say successful training 47_______ (base) on a simple rule: preparation. Dogs need to be exposed 48_______ (repeat) to the environment, to loud noises, to sounds so that when this experience happens to them on a daily basis, they're able to act in a way that they're used to acting and that they don't get excited.
Dog owners who 49_______ (attend) the training at Air Hollywood K9 Flight School since it was opened say they now feel much more at ease about future 50_______ (flight). Their dogs also seem ready for takeoff.
