The computer is one of the most essential things. We can use computers to do a lot, such as doing homework ,sending emails. Computers are very conveniet to use and welcomed by people, but they also have disadvantages.

对比一下吧.是不是对的?我都帮你把语法改了你对比一下不同之处。不过如果是写作的话，其实还是有更好的表达方式。你用的句式普遍比较简单，而且突出逻辑关系的关联词比较少，如果有时间的话，不妨改进一下。