表一类人或事,用定冠词和不定冠词有什么区别?例如：The tiger and the cat are of the same family of mammalsA dog is an animal that is often kept as a pet上面两个句子可互换吗?

表一类人或事,用定冠词和不定冠词有什么区别?例如：The tiger and the cat are of the same family of mammalsA dog is an animal that is often kept as a pet上面两个句子可互换吗?
表一类人或事,用定冠词和不定冠词有什么区别?
例如：The tiger and the cat are of the same family of mammals
A dog is an animal that is often kept as a pet
上面两个句子可互换吗?

表一类人或事,用定冠词和不定冠词有什么区别?例如：The tiger and the cat are of the same family of mammalsA dog is an animal that is often kept as a pet上面两个句子可互换吗?
不可以互换
第一句子表示特指,老虎和猫属于同一哺乳动物家族 如果用a,就变成一只老虎和一只猫了
第二句子表示泛指：狗经常被当做宠物来养.用the dog变成特指那一条狗