Put the articles (a/an, the or zero article (no article) in the sentences

Present Simple
• I always close the window at night
• Our lesson starts at 10 o'clock
• The Earth goes around the Sun.
• The prince gets on his horse and rides away.
Past Simple
• I flew to London last year.
• They graduated four years ago.
• Princess Diana visited a lot of schools.
• I woke up, took a shower, got dressed and went out.
• I took music courses when I was 9 years old.
Future Simple.
• We'll visit Paris one day.
• It won't be easy to open that door.
• I'll meet you and tell you a story
• I'm afraid the rain won't (will not) stop soon.
• I'll visit you a few times while I'm in UK