have no choice but to do sth.除了...别无选择
have no choice but to accpet his invitation.
我除了接受他的邀请没有别的选择.
I have no choice but to believe what you're saying.
我除了相信你说的话别无选择.
have nothing to do but do sth.除了...什么也没做
例如：I had nothing to do but slept all the time last Sunday.
(我上周日除了睡觉什么也没有做.)