10 . 阅读下面短文，在空白处填人1个适当的单词或括号内单词的正确形式。
The first creature 1 (orbit) our planet was just 2 years old. Her name was Laika.She was a good dog. Her 1957 flight paved the way for space 2 (explore) when scientists wondered 3 it was lethal (致命的) for living things.
Humans are explorers since the dawn of civilization. We 4 (attract) over the horizon to find food or more space, or just to see what beyond those trees or mountains or oceans. Our ability to explore reached new heights. Airplanes shortened distances, simplified travel and showed us Earth from 5 new aspect. By the middle of the last century, we aimed even 6 (high).
Our first steps into space began. Laika 7 (follow) into orbit four years later by the first human,Yuri Alekseyevich Gagarin. Space travel is nothing like in the movies. Getting from A to B requires complex calculations 8 (involve) inertia (惯性) and gravity. Space is also dangerous. More than 20 astronauts have died while doing their jobs.
That hasn’t stopped people from signing up and blasting off. NASA’s Apollo program had ended 9 private companies are readying their own space programs. A company 10 (name) SpaceX is hoping to land civilian astronauts on Mars. Maybe you’ll be a member of them. Don’t forget to bring your dog.
