Welcome to the Mars shuttle! You will find a few u________ things in the bag under your seat. You can use them on our trip and a________ we arrive. Please take out your bag now and become f________ with the items in it.

　 Your air tank will allow you to b________ outside on Mars. See the harness on the tank? You use it to carry the tank on your back. The tube coming out of the tank will carry air to your helmet. Inside the helmet, you can find a m____________. If you go out of your house on Mars, you can talk to your family members i________ using it. And these s________ space boots will allow you to walk on Mars. You also have a pair of special sunglasses for the trip. This will protect your eyes from the strong sunlight. Use your space timer instead o_______ a normal watch. Time passes differently on Mars and you don’t want to m__________ the shuttle back. In the bag, there are some vitamin pills for you if you feel s________ on the trip. Lastly, remember to wear this temperature control suit. It will help your body adjust to the temperature on Mars.　

1.u___________　 2. a__________　 3. f____________　 4. b___________

First of all ; in the form of pills ; At present; three-eighths ; take exams ;　

____________, it may be difficult to imagine that we will live on the planet Mars by 2100 because Earth is becoming more and more crowded and polluted.____________, transport should be better because the journey to Mars might take only a short time in space shuttles that travel ____________ ________. Scientists should be able to develop plants that ____________ the food and oxygen that we need. Humans on Mars have to wear special boots to make themselves heavier because the gravity is only about ____________ of that on Earth. Every student can study and ____________ in online schools because he will have a computer at home ____________ an inter-planet computer network. However, food on Mars will not be the same as that on Earth because it will probably be ____________ and the journey to Mars will be very uncomfortable.

12. I heard they _________ (return) it already.

11. Tom says that they ________________ (play) basketball at six o’clock yesterday evening.

10. The teacher told his class that light _______ faster than sound. (travel)

9. Do you know the meeting about a survey _________ (conduct) on the Internet in Beijing?

8. I think it is ______ (high) possible that our teacher is in her office.

7. I think _________ (dry) food is the most important for an astronaut.

6. The heavy rain kept us from _________ (go) outside