1.Earth is becoming more and more __________ (crowd).
2...__________ (hope),we can start again.
3.This pair of boots looks very ____________ (fashion).
4.There will be no ___________ (pollute) on Mars.
5.____________ (science) are working hard to make the dream become true.
B.根據(jù)所給中文和句意,填入正確的單詞.
6.___________(地球引力) will be a problem for the early settlers on Mars.
7.Humans need food,water and air to __________(生存)
8.Power pack can __________(提供) energy for the spacesuit.
9.A space sleeping bag is used to be fixed to the walls to prevent __________(飄浮).
10.Before the Project of Sanxia,many _________ (移民) left their hometown.
C.用所給動(dòng)詞的正確形式填空.
11.The news makes her __________ (feel) sad.
12.By 2100,we will spend only a few hours _________ (travel) to Mars in space shuttles.
13.Earth will be too polluted _________ (live) on.
14.The speech given by the expert is worth _________ (listen) to.
15.The policeman stops the children from _________ (play) football in the street.