Use past tenses, present perfect or past perfect tenses to complete these sentences

three clients since the morning.(contact)
i couldn't help you. problems.(not understand)
does he know about yet? (tell)
bill admitted that he catalogue to the agency. (not send)
as soon as i the message, i my house. (get, leave)
while maggie new jumper, jill and i (knit, read).

She has contacted three clients since the morning. (contact)

I couldn't help you. I didn't understand your problems. (not understand)

Does he know about it? Have you told him yet? (tell)

Bill admitted that he hadn't sent the catalogue to the agency. (not send)

As soon as I got the message, I left my house. (get, leave)

While Maggie was knitting a new jumper, Jill and I were reading. (knit, read).