A dinosaur’s long tail _____ (can / could) help it keep its balance as it ran.
could
Scientists thinks that the Parasaurolophus _____ (can use / could use / could using) its loud call to warn the others when a meat-eating dinosaur was near.
could use
Some dinosaurs could _____ (running / to run / run) quite fast.
run
(Could dinosaurs / Dinosaurs could) _____ make noises?
Could dinosaurs
Dinosaur _____ (can’t / couldn’t / could) give birth.
could
Nowadays, scientists _____ (can / could) learn about dinosaurs by studying their fossils.
can