(+) She ............. (work) as a firefighter last year.
She worked as a firefighter last year.
(-) The firefighters ......... (not, put off) the fire last night.
(-) The firefighters didn't put off the fire last night.
(+) The chef ........ (cook) a delicious meal last Thursday.
(+) The chef cooked a delicious meal last Thursday.
(+) Scientists ........ (do) experiments the last year.
(+) Scientists did experiments the last year.
(+) Last weekend, the police officer ....... (arrest) the thief.
(+) Last weekend, the police officer arrested the thief.
(-) Last Wednesday, the police officer ........ (not, find) the criminal.
(-) Last Wednesday, the police officer didn't find the criminal.
