My kitten got lost again yesterday. I（ ）never have let it go by itself.
A、
might
B、
should
C、
would
D、
could
【正确答案】：B
【题目解析】：
这里空格后为have done的形式，所以考查是对过去的猜测或者虚拟，might have done：过去可能做了（不太肯定）；should have done：本该做却没做；would have done：本想做却没做；could have done：可以是虚拟也可以是对过去的猜测。根据句意用should have done。选B。句意：我的小猫昨天又迷路了。我不该让它自己走的。