Recently, I heard that one of my friends wanted to change his major after one-year learning because he found that he had no interest and motivation in learning this major. From my point of view, it is not wise to change major halfway. 
最近，我听说我一个朋友说经过一年的学习后他想换专业，因为他发现他对现在这个专业没有任何的兴趣和动力。从我的角度来看，中途换专业是不明智的。
There are several disadvantages of changing major halfway. In the first place, changing major halfway means that we spend much time, energy and money in the last major but do not mastered the whole knowledge of that major yet. Second, changing major halfway needs a great resolution and we will face much pressure from others. Finally, changing major halfway may increase the burden of our family finance in that we need to spend another amount of money on another major. In addition, if we change our major halfway, we will lose a chance to find out our potential. Lack of persistence and willpower, we are difficult to be successful. 
中途换专业有几点弊端。首先，中途换专业意味着我们要花更多的时间，精力和金钱在后面的专业上，却还不能全面的掌握该专业的知识。第二，中途换专业需要很大的决心而且我们要面临来自其他人的压力。最后，中途换专业可能会增加我们的家庭经济负担，因为我们需要花另外一大笔钱在另一个专业上。此外，如果我们中途换了专业，我们就会失去一个发现我们潜能的机会。缺乏毅力和意志力是很难成功的。
In short, it is not advocated that we change major halfway. Therefore, we had better take all aspects into consideration when we are choosing major so that we can avoid change major halfway. Once we choose a major, we should try our best to learn it better.
总之，不主张中途换专业。因此，在选择专业的时候我们最好全面考虑清楚，这样我们就可以避免中途换专业。一旦我们选择了一个专业，我们就应该尽最大努力把它学好。