37.—— Would you have called her up had it been possible?Yes,

37.—— Would you have called her up had it been possible?Yes,but I ________ busy doing my homework.A.was B.were C.had been D.would be 38.His tired face suggested that he ________ really tired after the long walk.A.had been B.was C.be D.should be 为什么选a.b