Correct
书简
/ shūjiǎn /
Strokes
Definition
(literary) letter
Example
As a Noun
letter; correspondence
1
Zhèngshì
正式
shūjiǎn
书简
standard/formal letter
2
Shāngwùshū
商务书
jiǎn
简
business/commercial letter
3
Nìmíng
匿名
shū
书
jiǎn
简
anonymous letter
4
Jīmì
机密
shūjiǎn
书简
confidential letter