Phrases in the sentences given below are underlined.Choose the option which you feel can replace all of the underlined phrases.If there is no improvement needed,choose "No improvement required".
1.Before anyone could cast off,they had hacked the computers.
2.They could not solve the issue because the problem was hard to call on.
3.We need to read the book otherwise we would never call around the method.
1
Catch out
2
Cave in
3
Check out
4
Catch on
5
No improvement required