阅读理解 真题 Most people have had a dog or wanted one as their companion at some time in their lives . If you are thinking of buying a dog , however , you should first decide what sort of companion you need and whether the dog is likely to be happy in the surroundings you can provide . Specialist advice is available to help you choose the most suitable breed of dog . But in part , the decision depends on common sense . Different dogs were originally developed to perform specific tasks . So , if you want a dog to protect you or your house , for example , you should choose a breed that has the right size and characteristics . You must also be ready to devote a good deal of time to train the dog when it is young and give it the exercise it needs throughout its life , unless live in the country and can let it run freely . Dogs are demanding pets . Cats love the house and so are satisfactory with their place which is secure , but a dog is loyal to its master and consequently wants him to show proof of his affection . The best time to buy a baby dog is when it is between 6 and 8 weeks old so that it can transfer its affection from its mother to its master . If baby dogs have not established a relationship with the human being until they are over three months old , their strong relationship will always be with dogs . They are likely to be too shy when they are brought out into the world to become good pets . Why is it advised to buy a baby dog under l three months old ?