Nowadays, it is more convenient and easier for people to travel to other countries. 

Is this a positive or negative development?

应对这道小作文题目，学生在开头是这么铺垫背景的：

These days, a larger number of people decide to travel abroad. I believe there to be more advantages than disadvantages with regard to this development.

※一般现在时一般用在客观真理或经常性频繁性发生的事情上，那么我们在铺垫背景这类“当下的现象”的时候，尤其在原句已经涉及到these days的情况下，一般建议用现在进行时is/are doing或现在完成时have/has done。

教师修改后如下：

There days, a larger number of people are deciding to travel abroad. I believe there to be more advantages than disadvantages with regard to this development. 

※ 所以，将动词decide调整为are deciding，更切合规范用法；

※ 另外，there to be结构是我们最熟悉的there be结构的不定式用法，该结构可以跟在believe后作为动词的宾语，同理还可以跟在一系列接不定式的动词诸如want, intend, expect, consider等之后，例如: The WWF estimates there to be fewer than 400 Sumatran tigers living in the wild.