若a是正数，a-b的结果是(   )

台湾的经济特点

有关发达国家与发展中国家的叙述，错误的是（　　）

                                                                                                                      钟山即事   
                                                                                                                         王安石
                                                                                                 涧水无声绕竹流，竹西花草弄春柔。
                                                                                                 茅檐相对坐终日，一鸟不鸣山更幽。