Подскажите, , ответ where the taxi arrived? a) did they sit b) were they sitting c) will they sit d) have they been sitting

"were they sitting"
или же "did they sit "и то,и то подходит

Поставьте следующие предложения во множественное число.
1. His wives are not ready yet.
2. Are there mice under the bed?
3. The high mountains are very cold at the top.
4. There are large shipping companies in Istanbul.
5. There are only three holidays this month.
6. These classes are very boring.
7. My feet are tired.
8. There are two parties this weekend.
9. Those are large boxes.
10. These are expensive watches.

Поставьте следующие предложения в единственное число.
1. Is there a goose on the pond?
2. Our enemy is near.
3. This watch is broken.
4. That Rock band is loud.
5. There is a fish in the sea.
6. There is a potato for dinner.
7. That knife is very sharp.
8. Your child is very good. .
9. The cliff is dangerous.

1. His wives are not ready yet. 

2. Are there mice under the bed?

3. High mountains are very cold at the top.

4. There are large shipping companies in Istanbul. 

5. There are many holidays this month. 

6. These classes are very boring. 

7. My feet are tired. 

8. There are parties this weekend. 

9. Those are  large boxes. 

10. These are expensive watches

1. Is there a goose on the pond? 

2. Our enemy is near. .

3. This watch is broken. .

4. This Rock and Roll band is loud. .

5. There is a fish in the sea. .

6. There is a potato for dinner. .

7. This knife is very sharp. .

8. Your child is very good. .

9. The cliff is dangerous.