Past continuous structure.

a Tbook Twas Treading TThe Tbear. T

bear Tplaying Twas TThe Tchess. T

playing Mchess Mwasn't MMasha. M

was Moatmeal MMasha Mpreparing. M

were Tfighting Tbirds TThe. T

volcanoes Texploding Tweren't TThe. T

swimming Tweren't Tturtles TThe. T

The Twere This Tbaby Tand Trowing Tman. T

It Iraining Iwasn't. I

crying Twas TThe Tduck. T