72-the factors that determine variation in register are:
a- field and tenor
b-field and mode
c-field, tenor and mode
73-........ refers to the subject matter of the discourse
a- field
b-mode
c-tenor
74-....... refers to the role being played by the speaker
a- field
b-mode
c-tenor
75- refers to the medium of communication, e.g. speech or writing
a- field
b-mode
c-tenor