You can use
sed -i "N;/
.*text: 'About'/"'!P;D' file.txt
Details:
-i
- file inplace replacement mode on
N
- opens a two-line window throughout the whole file (it reads the next line prepended with a newline into pattern space)
.*text: 'About'
matches a newline, then any text and then text: 'About'
!P;D
- if there is a match, do not print the first line, then delete the first line and repeat.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…