Correct

昧于

/ mèi yú / 
Strokes

Example

As a Verb

be ignorant of; fail to understand

1
Mèi
昧
yú
于
shìshí
事实

be ignorant of the facts; be unaware of the truth

2
Mèi
昧
yú
于
shìlǐ
事理

lack common sense

3
Mèi
昧
yú
于
shìdào
世道
chángqíng
常情

be too ignorant of the ways of the world

4
Mèi
昧
yú
于
qínglǐ
情理

be void of reason