虽然他试图保持冷静，但颤抖的声音泄露了他的恐惧。

Though he tried to stay calm, his shaky voice was ___betraying his fear.

她无法原谅丈夫背叛了他们的婚姻誓言。

She couldn't forgive her husband for ___betraying their marriage vows.

他假装是朋友，却通过告密背叛了同事。

He pretended to be a friend but ended up ___betraying his colleague by reporting him.