How do you account for the context function as indication of ref

How do you account for the context function as indication of referents?
【正确答案】：Englist has a large number of words such as now/then, here/there,/you. this/that. which are often used to refer directly to people, time, place, etc. Without clear context. the reference car. be very confusing. For example. the word now always means the time of speaking naturaily referring to a past time when the speech took piace in the past or a present moment if the person is spcaking. It is the same with all referring expressions. Even a phrase like the Prime Minister may bring ahout ambiguiy without adequate verbal context. for it can be used to refer to any of the Primne Ministers in British history.