tolong yang jago bahasa inggris nomer 4

a. (+) they sit in the garden
(-) they don't sit in the garden
(?) do they sit in the garden?

b. (+) they sat in the garden
(-)they didn't sit in the garden
(?) did they sit in the garden?

c. (+)they have just sat in the garden
(-)they haven't sat in the garden yet
(?)have they sat in the garden yet?

*maaf kalau salah