could ,must do,must be反意疑问句后面分别用什么

could ,must do,must be反意疑问句后面分别用什么 Do you know where your father is?I think he______on the computer A.must chaA.must chatB.must be chattedC.could chatD.could be chatting 是must to do还是must doing 还是must do? something must do,something must not do must 加to must must not do Must you do not must doing还是must to do? They who can't do as they would ,must do as theyThey who can't do as they would ,must do as they could.翻译 Do you know where your father is?I think he______on the computerA.must chatB.must be chattedC.could chatD.could be chatting must do sth must not do sth 造句 各三个 must do sth 还是 must to do sth must do sth must not do sth 造句 各三个 change...yes,you must do it!must do! you must do like me. we must do more英译汉 one must do one is . Sb must do sth造句