1) Before I left for work yesterday, I drank a cup of coffee. 2) By the end of the week I will have finished working on my report. 3) Ten years ago I flew to Paris. 4) His dad and brother are cycling to the shop now. 5) You arrived at the cinema late. The film had already started. 6) We will have done the washing by 8 o'clock next Monday. 7) Most of the Earth's surface is covered by water. 8) While I was on holiday, my camera was stolen from my hotel room. 9) We went to Laila's house but she was not at home. 10) I have never been in Spain.

Before I left for work yesterday, I drank a cup of coffee.
This sentence uses the past simple tense ("drank") to describe an action that was completed before another action in the past ("left for work"). It shows a sequence of events.

By the end of the week I will have finished working on my report.
Here, the future perfect tense ("will have finished") is used to express an action that will be completed by a specific point in the future ("by the end of the week").

Ten years ago I flew to Paris.
This sentence uses the past simple tense ("flew") to talk about a completed action in the past, specifically an event that occurred a fixed amount of time ago ("ten years ago").

His dad and brother are cycling to the shop now.
This sentence uses the present continuous tense ("are cycling") to describe an action that is happening at the moment of speaking ("now").

You arrived at the cinema late. The film had already started.
The first part of the sentence uses the past simple tense ("arrived"), while the second part uses the past perfect tense ("had already started") to indicate that the action of the film starting happened before another past action ("arrived").

We will have done the washing by 8 o'clock next Monday.
The future perfect tense ("will have done") is used here to describe an action that will be completed before a specific time in the future ("by 8 o'clock next Monday").

Most of the Earth's surface is covered by water.
This sentence uses the present simple tense ("is covered") to express a general fact or truth that is always true.

While I was on holiday, my camera was stolen from my hotel room.
This sentence combines the past continuous tense ("was on holiday") to show an ongoing action in the past, and the past simple tense ("was stolen") to describe a completed action that occurred during that time.

We went to Laila's house but she was not at home.
The past simple tense is used in both parts of the sentence ("went," "was not") to describe two actions that happened in the past. The second part explains that, despite going to her house, she was absent at that moment.

I have never been in Spain.
This sentence uses the present perfect tense ("have been") to describe a situation that started in the past and continues to the present. The word "never" emphasizes that the action has not occurred up until now.