task 4　　【passage】：Progress explanation means somebody tells sb else how to do some work. Progress explanation有两类：1、directive explanation。teach people how to carry out a project step by step. with instruction 2、informational explanation。just tell people a general idea about it ,without instruction, people are not told how to finish the task themselves.　　【lecture】：the professor use two examples to illustrate two types: 1、he bought a cell phone recently，但不会put the telephone number into cell phone. His friend taught him how to enter the name and phone number step by step,for example, first input a number then a name . but one night the prof saw on Tv a program , says how signal is transmitted from one cellphone to another when dialed, by atenas and satellites, but it didn’t tell how to use the phone, so the prof didn’t know how to use the phone even after watching the program 　　question: how does the prof illustrate the definition of progress explanation using examples 　　两种process，一种directive,还有一个informational，文章解释了这两个概念。教授说自己昨天买了个新手机，不知道怎么输号码，然后一个朋友走进来教他使用，然后他就能自己用了。然后说那天在电视上看到report，讲手机的原理，什么什么的，但是知道了这些原理也不知道怎么用手机。问题：用教授的例子解释这两个概念。