It is true that full time students should devote their time to studying. Personally, I agree with the idea that it is also necessary for students to participate in other activities, because I believe that they are equally important.
On the one hand, to focus on studying is essential in order for students to be more competitive on job hunting. For example, undergraduates all need to acquire job-related knowledge and skills for career preparation. Most students consider it a priority to study for seeking jobs. If they spent all of their time on entertainment or other non-academical things, they might find it difficult to compete with others. Lower academically achieving students, for instance, pay less attention to studying so that they cannot work in professions such as doctor, teacher and lawyer, because these jobs require applicants to have professional knowledge.
Nevertheless, other activities are just as important as what students learn from university. Firstly, practical activities are extremely important for undergraduates to understand the knowledge they gained from text. Practical experience, for example, can make students comprehend the relationship between professional knowledge and practical application and master the skills which can be used in the future. Secondly, many undergraduates learn how to communicate effectively from their social parties, the voluntary service they organize, and the group video games they play, rather than the knowledge they acquire. Finally, students can improve their health if they usually take part in physical activities, which are also positive for their mental development.
In conclusion, while full-time undergraduates should spend amounts of time on studying, I believe that other activities are also essential for them.