Question

unit: discovering implied meaning
progress:
the movement of the progress bar may be uneven because questions can be worth more or less (including zero) depending on your answer
which sentence is in the past tense?
pandas may go extinct because of habitat loss.
teddy roosevelt, jr., the son of president and conservationist theodore roosevelt, is thought to be the first person ever to shoot a panda.
pandas don’t like other pandas and prefer to be alone.
a bone in the wrist of pandas evolved into an extra thumb.

Explanation:

The past - tense verb in "A bone in the wrist of pandas evolved into an extra thumb." is "evolved", which is the past - tense form of the verb "evolve". The other sentences use present - tense forms like "may go", "is thought", "don't like".

Answer:

A bone in the wrist of pandas evolved into an extra thumb.