Sure! Here are the correct forms of the verbs for each sentence:

**Question 10:** At the time the factory closed down, Sarah **had been working** there for five years.

**Question 11:** - Had she **been watching** TV for 4 hours before she went to eat dinner?

**Question 12:** She was very upset because I was late and she **had been waiting** for a very long time.

Let me know if you need any more help!