The astronauts could not have reached the moon without the invention of rockets. We live in the age of rockets, but do you know that rockets are not a modern
(1) __invention___ ? For centuries, rockets were used to entertain people. The Chinese used
rockets (2) __as__a__ fireworks. In the 13th century, rockets were first used in war. The
Mongols used rockets to attack a Chinese city in 1232. These early rockets could not
(3) ___fly_____very far. However, in 1885 a Russian scientist discovered a better fuel for rockets. This liquid fuel gave rockets much more power. Then in 1919 a new age of rockets began. In that year an American scientist, Robert Goddard, said that it was
(4 )___used___ to send a rocket to the moon! Goddard launched his first liquid-fuelled rocket in 1923. It flew 184 feet. Almost 12 years later, he sent a rocket 7,500 feet into the
air in 1935. Russian rockets sent the first (5) _flight_____ into orbit in 1957. Just 12 years
later the first man walked on the moon – thanks to rockets! Where will rockets take us next?
cs sai thì bạn ns để mình sửa nhé

1. invention

2. as

3. fly

4. used

5. flight