Finally, the pressure put on high school students by excessive schoolwork can cause serious stress, which is unhealthy physically and mentally. 此外，繁重的课业加诸在高中生身上的压力可能引起严重的情绪紧张，这对身心都有害。
The use of the mouse are operated in order to make the computer more convenient, to replace keyboard commands that cumbersome.
鼠标的使用是为了使计算机的操作更加简便，来代替键盘那繁琐的指令。
As we know, massive destruction of environment has brought about negative effects and even poses a great threat to man's existence.正如我们所知，大规模破坏环境带来负面影响，甚至造成巨大威胁人类的生存。