1. Neil Armstrong was a well-known person. He first walked on the moon.
=>Neil Armstrong, who first walked on the moon, was a well-known person
2. Shakespeare was born in 1564 and died in 1616. He wrote "Romeo and Juliet".
=>Shakespeare, who wrote "Romeo and Juliet", was born in 1564 and died in 1616
3. His house doesn't have electricity. It is in the forest.
=> His house which in the forest doesn't have electricity
4. Mars is the planet. It is close to the earth.
=> Mars, which is the planet, is close to the earth
5. James Watt was a great scientist. He invented the steam engine.
=> James Watt, who invented the steam engine, was a great scientist
6. We have visited Singapore twice. Singapore won the 1998 Tiger Cup
=> Singapore, where we have visited twice, won the 1998 Tiger Cup