单选题
1.00分
I have to go at once.
参考答案: B
参考解析: at once:马上。immediately:马上,例如:It's getting late.We must go back home immediately.越来越晚了,我们得马上回家。soon:很快,例如:We'll have lunch soon.我们很快就要吃午饭了。now:现在,例如:If we leave now we'll be there before dark.如果我们现在就离开,我们在天黑前就会到那里了。early:早,例如:Mary gets up very early.玛丽起得很早。选项B与题干中at once的含义相近,故答案为B。