Correct

透心儿

/ tòu xīnr / 
Strokes

Example

As a Verb

to the core; to the marrow

1
Zhè
这
luóbo
萝卜
dōu
都
kāng
糠
tòu
透
xīnr  
心儿
le
了
  
。

This radish has gone spongy to the core.