Jawaban:

(1.) Subject = Bella and Billy, to be = are
(+) Bella and Billy are cleaning the table.
(-) Bella and Billy aren't cleaning the table.
(?) Are Bella and Billy cleaning the table?

(2.) Subject = Shinta, to be = is
(+) Shinta is making the bed.
(-) Shinta isn't making the bed.
(?) Is Shinta making the bed?

(3.) Subject = My family and I, to be = are
(+) My family and I are having dinner.
(-) My family and I aren't having dinner.
(?) Are my family and I having dinner?

(4.) Subject = Nina, to be = is
(+) Nina is doing the laundry.
(-) Nina isn't doing the laundry.
(?) Is Nina doing the laundry?

(5.) Subject = My cat, to be = is
(+) My cat is sleeping on the sofa.
(-) My cat isn't sleeping on the sofa.
(?) Is my cat sleeping on the sofa?

Penjelasan:

Present continuous = kalimat aktivitas yg sedang dilakukan

Rules:

I
(+) I + am + verb-ing
(-) I + am not + verb-ing
(?) Am + I + verb-ing?

You/we/they/(.... and .....)
(+) You/we/they/(.... and .....) + are + verb-ing
(-) You/we/they/(.... and .....) + aren't + verb-ing
(?) Are + you/we/they/(.... and .....) + verb-ing?

He/she/it/(someone's name)
(+) He/she/it/(someone's name) + is + verb-ing
(-) He/she/it/(someone's name) + isn't + verb-ing
(?) Is + he/she/it/(someone's name) + verb-ing?

<(7o7)>