HSK 5 HSK V3
Correct

单元

/ dānyuán / 
Strokes

Definition

unit (forming an entity)/element/(in a residential building) entrance or staircase

Example

As a Noun

unit

1
Wǔ
五
háo
号
lóu
楼
sān
三
dānyuán
单元
312
312
shì
室

No 312, Entrance 3, Building 5

2
Kèběn
课本
qián
前
sān
三
gè
个
dānyuán
单元

first three units in a textbook