Nowadays it is more convenient and easier for people to travel to other countries, is it development a positive or negative effect?
参考范文：
Never before was travelling to alien countries so convenient and popular as in this century. This phenomenon is partially attributed to improved technology and cheap flight tickets. Facing this travel frenzy, some are concerned that it will bring about too many side effects whilst others insist that is should be supported and maintained.
Admittedly, cross-border travel has more downsides than one. Firstly, the carbon dioxide planes emitted is reported to be disproportionately more than that emitted by other transportation means. The carbon dioxide will lead to ozone layer thinning and thereby increase the probability of people contracting skin cancer. Moreover, being easier and more convenient to travel among countries means that some criminals could flee to other countries after committing hideous crime. This will pose a threat to local security and community stability.
