Use vi and vim shortcuts

 

 The number of rows from the cursor

① Insert mode because there is no way to use shortcut keys, so esc to switch to normal mode. yy p is copy and paste
the cursor to the fifth row: input 5yy; 5 replicate rows prompted
by p; 5 rows prompted more

② In the normal mode 5dd delete delete a row by row dd 5

③ inquiry with hello / hello; / keyword
input n Find Next

④ set the line number set nu
cancel the line number set nonu

⑤ locking caps to the bottom of a document Press g
gg to the first line of the document

⑥u revoked

⑦ cursor to row line 20
Step display line number set nu
Step 20 enter
the third step targeting shift + g