8. Did you hear that Ben was fired last month? He (work) for that import company for more than ten years and he (work) in almost every department. Nobody knew the company like he did.
9. Wait a minute, I (to carry) this box for you.
10. I (see) many pictures of the pyramids before I went to Egypt. Pictures of the monuments are very misleading. The pyramids are actually quite small.
11. Sarah (climb) the Matterhorn, (sail) around the world, and (go) on safari in Kenya. She is such an adventurous person.
12. Look! It (to rain) so we can't go to the beach.
13. Sarah (climb) the Matterhorn, (sail) around the world and (go) on safari in Kenya by the time she turned twenty-five. She (experience) more by that age than most people do in their entire lives.
14. (they / spend) their holidays in Paris last summer?
15. When Melanie came into the office yesterday, her eyes (be) red and watery. I think she (cry).
16. By the time we get to Chicago this evening, we (drive) more than four hundred miles. We are going to be exhausted.
7. At 6 o'clock on next Friday they (sing) the new song.
8. When he (wake up) yesterday, his mother (already / prepare) breakfast.
9. When Sarah goes on vacation next month, she (study) German for over two years. She should be able to communicate fairly well while she is in Austria.
10. (you / ever / see) a whale?

Did you hear that Ben was fired last month? He had been working for that import company for more than ten years and he had worked in almost every department. Nobody knew the company like he did.
Здесь нужен Past Perfect Continuous для длительного действия до прошлого момента: had been working. Второй глагол — Past Perfect, потому что речь о накопленном опыте до увольнения: had worked.

Wait a minute, I will carry this box for you.
Здесь используется Future Simple, потому что это спонтанное предложение помощи: I’ll carry this box for you.

I had seen many pictures of the pyramids before I went to Egypt. Pictures of the monuments are very misleading. The pyramids are actually quite small.
Действие “видел фотографии” произошло раньше другого действия в прошлом — “поехал в Египет”, поэтому нужен Past Perfect: had seen.

Sarah has climbed the Matterhorn, has sailed around the world, and has gone on safari in Kenya. She is such an adventurous person.
Здесь говорится о жизненном опыте Сары до настоящего момента, поэтому используется Present Perfect: has climbed, has sailed, has gone.

Look! It is raining so we can’t go to the beach.
Слово Look! показывает, что действие происходит прямо сейчас, поэтому нужен Present Continuous: is raining.

Sarah had climbed the Matterhorn, had sailed around the world and had gone on safari in Kenya by the time she turned twenty-five. She had experienced more by that age than most people do in their entire lives.
Фраза by the time she turned twenty-five указывает на действия, завершившиеся к определённому моменту в прошлом, поэтому нужен Past Perfect.

Did they spend their holidays in Paris last summer?
Есть указание на завершённое время в прошлом — last summer, поэтому используется Past Simple: Did they spend...?

When Melanie came into the office yesterday, her eyes were red and watery. I think she had been crying.
Глаза были красные в момент прихода — Past Simple: were. Причина этого состояния началась раньше и продолжалась некоторое время, поэтому: had been crying.

By the time we get to Chicago this evening, we will have driven more than four hundred miles. We are going to be exhausted.
Действие будет завершено к определённому моменту в будущем, поэтому используется Future Perfect: will have driven.

At 6 o’clock next Friday they will be singing the new song.
В указанное время в будущем действие будет в процессе, поэтому нужен Future Continuous: will be singing.

When he woke up yesterday, his mother had already prepared breakfast.
Он проснулся вчера — Past Simple: woke up. Завтрак был приготовлен раньше этого момента — Past Perfect: had already prepared.

When Sarah goes on vacation next month, she will have been studying German for over two years. She should be able to communicate fairly well while she is in Austria.
К моменту поездки в будущем действие будет длиться уже более двух лет, поэтому нужен Future Perfect Continuous: will have been studying.

Have you ever seen a whale?
Вопрос о жизненном опыте до настоящего момента, поэтому используется Present Perfect: Have you ever seen...?