More and more people using mobile phone and computer to instead of letters.这句话的mobile phone and computer 后面要加S
问题描述：
More and more people using mobile phone and computer to instead of letters.
这句话的mobile phone and computer 后面要加S
答
不用加S
答
越来越多的人使用手机和电脑来代替信件。
答
不用,指代一类.可是letter加个s干什么呢?加the,特指一类事物.