1 . “We are running out of space and the only places to go to are other worlds.... Spreading out may be the only thing that saves us from ourselves. I am convinced that humans need to leave Earth.” These are the words of the famous scientist Stephen Hawking, spoken at a science festival in Norway in 2017, a year before his death.

Hawking was not alone in this view. Many experts feel that the only way for humanity to last far into the future is to colonize （移民） other planets. That way, if an asteroid （小行星）, a terrible disease, nuclear war, or some other disaster strikes Earth, civilization would still have a chance. Mars is one of the ideal destinations. NASA, SpaceX, and Mars One all have plans to send humans there. “Either we spread Earth to other planets, or we risk going extinct,” SpaceX founder Elon Musk said at a conference in 2013.

But not everyone agrees that colonizing Mars or any other planet is such a great plan. The most common argument against going is that it’s just too expensive or dangerous. It will take huge amounts of money and other resources just to get people there, let alone set up a place for them to live. It’s not even clear if humans could survive on Mars.

Maybe all the time and money people would pour into a Mars mission would be better spent on more urgent projects here on Earth, like dealing with poverty or climate change. Some experts argue that handling a problem like an asteroid strike or disease outbreak while staying here on Earth would be much easier and less expensive than surviving on a new planet.

In addition, moving to a new planet could harm or destroy anything that already lives there. Human visitors change or damage the Martian environment. Some feel that’s too much of a risk to take.

1. What is Stephen Hawking’s view according to paragraph 1?

A．The earth is likely to blow up.

B．Humans are using up natural resources on Earth.

C．It is necessary to spread out to other planets.

D．We should explore our world to save ourselves.

2. Why are many experts in favor of leaving Earth?

A．Because there will be a nuclear war in the near future.

B．Because human can live better on Mars.

C．Because it is a way for earth civilization to last.

D．Because it is a way to test our space technology.

3. Which of the following may those who are against colonizing Mars agree?

A．It is wiser to deal with problems on Earth.

B．It is easy to stop a disease outbreak.

C．Human will not survive on Mars.

D．It is impossible to set up a place for people to live on Mars.

4. What is the best title of passage?

A．Leaving Earth to Other Planets	B．Should We Colonize Mars?
C．New Home on New Planet	D．A Mar Mission Is on The Way