ffice" />corporate profits peaked in the fourth quarter of 1988 and have slipped since then, as many companies have been unable to pass on higher
(E) yet are slipping since then, because many companies were unable to pass on higher costs
OG: In E, yet also requires a comma before it, are slipping with since then is illogical, and were unable represents an ungrammatical tense shift.
why a comma is needed before yet? yet is also a conj right? anybody got idea? Thanx