Lower advanced level

The advanced learner can use her skills to assist the lower-level learner. The lower-level learner is able to learn from the more advanced learner.

高水平学习者可利用其能力帮助低水平学习者，而低水平学习者则能从高水平学习者处学到很多。

This prevents the advanced students from getting bored and also prevents the lower-level students from becoming nervous or tense when they realize people have finished their assignments before them.

这样既可以防止高水平学生感觉厌烦，又不会使低水平学生在看到有人完成作业时感觉着急。

These more advanced shells not only lower the training requirements for users, but they also simplify the use of increasingly powerful (and higher level of abstraction) commands.

这些高级的shell不仅降低了使用难度，而且还简化了日渐强大的(以及更高的抽象层上)命令的使用。