请选择DCBA(u'v1H+C5J The children went home from the grammar school，their lessons _________ for the day.6_6H1e:M-R5C0J'k0x7_
A.finishing6_6H1e:M-R5C0J'k0x7_
B.finished6_6H1e:M-R5C0J'k0x7_
C.had finished6_6H1e:M-R5C0J'k0x7_
D.were finished6_6H1e:M-R5C0J'k0x7_