【答案解析】The chart above gives us a vivid description about the time boys and girls spend on the Internet. Both genders take roughly the same amount of time on obtaining news, sending and receiving emails and studying. However, there are substantial differences regarding the time spent on chatting and playing games. Girls spend as high as 45% of their time chatting online, which is twice more than that of boys. (此处的比较结构使用得非常准确，as high as...词组使用也很得体) By contrast, boy students claim that they have used 45% of their time playing games on the Internet, compared with only 12% of that of girls.
The differences revealed by the chart could be explained by physical discrepancy of the genders. (此句归纳很精准，选词也非常有水平，如discrepancy。但是时态要和前文保持一致，均要修改为一般现在时，revealed改为reveal, could be...改为can be...) In general, girls tend to be more talkative and enjoy interactions with people, and this is likely to be the reason why they have spent much time chatting online. Boys, however, show less interest in dealing with others than playing games.
Interestingly, only a small proportion of time is used for study of both genders (20%), which suggests that the students regard the Internet as a relaxation and entertainment rather than a tool for study.