现在没有人知道中国的背包旅行现象(backpacker phenomenon)确切的渊源，不过成千上万的人已经加入到这种生态自助型的(eco-centric)新旅游活动中。而想要成为“驴友”(friend of donkey)，你不一定要年轻力强，也不一定要囊中富足。“驴友”们很多不过是口袋空空的(impoverished)学生，每一次旅途都需要精打细算，而另一些人则可能已到了中老年。有的人徒步到偏远的地方(remote places)泡上好几个月，有的在周末来一次远足，他们总是准备着探索旅程中新的道路，发现惊喜。

A. They pay less attention to their linguistic behavior.
B. The fewer use of the deferential linguistic forms.
C. They confuse male and female forms of language.
D. They employ very strong linguistic expressions.

A. Press the "process" key.
B. Insert his card.
C. Memorize his personal number.
D. Insert some coins.