Choose the underlined part A, B, C or D that needs correcting

hoose the underlined part A, B, C or D that needs correcting.
1. Having leisure activities are truly important to the elderly.
A. Having
D. elderly
B. are
C. to
2. Although she wanted to go to the museum, she decided staying at home.
A. Although
D. staying
B. wanted to go
C. decided
3. Parents are concerned that their kids may be spending too many time on screens.
A. concerned
B. spending
C. too many
D. on screens
4. Collecting coins is exciting, but it can also be relaxed.
A. Collecting
B. is
C. exciting
D. relaxed
5. Cloud watching sound weird, but Hang adores it.
A. Cloud watching B. sound
C. but
D. it
6. For some young people, enjoyment involves sitting in front a computer playing games.
A. For some
B. involves
C. in front
D. playing games
7. His parents are thinking of banning him on using the computer.
A. thinking
B. banning
C. on
D. using
8. When you play games online, be carefully when making friends with strangers.
C. making
B. carefully
D. with
A. games