作为古典政治经济学的杰出代表和理论体系的建立者，斯密认为经济学要研究如何增加国民财富。斯密认为，增加国民财富的途径是（   ）

①降低地租，增加资本积累            ②鼓励出口，禁止或限制进口

③通过分工提高劳动生产率            ④自由放任，提高资本利用率

增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1）每处错误及其修改均仅限一词；

2）只允许修改10处，多者（从第11处起）不计分。

Ladies and Gentlemen,

    We are so happily that you have taken your time off to be with us today. As you know it, our school had a long history of more than 100 years. With great pleasure we have prepared several event that we hope will please you. On 10: 00 am, our headmaster will give welcome speech in the school hall. Followed the speech is a tour of our school history exhibition at 10:30. The exhibition was laid out in the classrooms on the second floor. But then we will show you around our science, labs which you can see some new advanced equipment. Have fun!