Past perfect continuous negative 10 - tutto inglese - Imparare l'inglese gratis on line

The researchers (analyse) those samples before the grant.
They (construct) any major projects before this.
She (restore) furniture before she found the antique desk.
He (study) hard before he realized his grades were slipping.
We (prepare) for such scenarios before the crisis.
They (monitor) the system before the errors started.
She (practice) regularly before the tournament.
I (refine) my methods before the review.
He (conduct) field research before this job.
We (foster) any pets before we met the stray cat.