4 B Past modals

a   2 might have been expecting  3 must have just come back 4 can't have been 5 must have heard 6 might not have known 7 might have been surprised 8 must have known 9 can't have been 10 might have wanted.

b  2 shouldn't have used 3 shouldn't have broken up 4 should have come 5 should have waited 6 shouldn't have worn 7 should have told 8 shouldn't have bought.