Answer:
1. The film house <u>has</u> not <u>developed</u> the pictures yet.
2. Fred<u> </u><u>will have left </u>before Erin's arrival.
3. Florence <u>has been</u> a very gracious hostess.
4. Andi <u>had lost </u>her transfer by the end of the bus ride.
5. By tonight, I <u>will have finished</u> my assignment.
6. Before the discovery of the buried chest, joe <u>had</u> not <u>believed </u>in buried treasure.
7. We <u>have worked</u><u> </u>over an hour on one math problem.
8. Until his college years, Carl <u>had </u>not <u>decided</u> on his career.
9. The snow plows <u>had cleared</u> our street before the really heavy snow.
10. <u>Have</u> the Ortons <u>found</u> their dog yet?
Explanation:
1. Has is the auxiliary verb in the sentence while developed is a past participle. The combination is a present perfect tense.
2. "Will have left" is a future perfect tense.
3. "Has been" is the present perfect tense.
4. "Had lost" is a past perfect tense.
5. "Will have finished" is a future perfect tense.
6. "Had not believed" is the past perfect tense.
7. "Have worked" is a present perfect tense.
8. "Had not decided" is a past perfect tense.
9. "Had cleared" is a past perfect tense.
10. "Have the Ortons found" is a present perfect tense.
