题干
--- Jim failed again in the maths examination.
--- Don't scold him too much. _____ , he has tried his best.
--- Don't scold him too much. _____ , he has tried his best.
A：After all
B：Above all
C：At all
D：In all
答案(点此获取答案解析）
A
的概率分布如下表，且
，则
的值为
