1. We must cook this dish with tomatoes, or we don't have any in the fridge.

• Explanation: "or" is used to express a choice or alternative. Here, it means that if we don't have tomatoes, we can't cook the dish.

2. I don't get any money because all banks were closed.

• Explanation: "because" is used to introduce a reason. The speaker doesn't have any money because the banks were closed.

3. Lucy was doing her homework while her friends were playing games.

• Explanation: "while" is used to show that two actions were happening at the same time. Lucy was doing her homework, and at the same time, her friends were playing games.

4. We can play chess or we can watch TV.

• Explanation: "or" is used again to present choices. We can choose to play chess or watch TV.

5. David didn't pay attention to the lesson yesterday, so he couldn't understand anything.

• Explanation: "so" is used to show a result or consequence. Because David didn't pay attention, he couldn't understand anything.

6. Tom didn't want to visit his uncle, but he pretended to be ill.

• Explanation: "but" is used to show a contrast between two ideas. Tom didn't want to visit his uncle, but he pretended to be ill to avoid it.

7. The postman couldn't deliver the mail because the roads were constructed.

• Explanation: Again, "because" is used to introduce a reason. The postman couldn't deliver the mail due to road construction.

8. I don't eat a lot of Indian food because it's too spicy for me.

• Explanation: Once more, "because" is used to explain a reason. The speaker doesn't eat much Indian food because it's too spicy.

9. They don't have play football, nor do they play badminton because they hate sports.

• Explanation: "nor" is used to connect two negative statements. They neither play football nor badminton because they dislike sports.

10. You have to eat well, or you'll get sick.

• Explanation: "or" is used again to present a choice or consequence. If you don't eat well, you will get sick.