文档介绍：四动词不定式
不定式作主语和宾语
Sometimes ____ to place physics and chemistry into separate categories.
A. that is difficult B. is difficult C. it is difficult D .that it is difficult
The teachers don’t know ____ to start and run a school.
A. what it takes B. what they take C .what does it take D. what takes
Because air is pressible, ____ to define a clear upper boundary of the atmosphere.
A. it is impossible B. impossible is C. so the impossible D. is the impossibility
The Homestead Act of 1862 ____ to acquire land at a small cost.
A. made possible B. made it possible C .made the possibility D .possibly made
To what extent will future scientific discoveries ____ possible the lengthening of the human life?
A. be made B. make it C .make D. be made it
X-rays are able to pass through objects and thus make ____ details that are otherwise impossible.
A. it visible B. them visible C. visibly D .visible
Digital recording has made ____ a significantly wider dynamic range in recorded music.
A. for the possibility B. the possibility is C .it is possible D. possible
The discovery of the halftone process in photography in 1881 made ____ photographs in books and newspapers.
A. the possible reproduction B. possible to reproduce
C .it possible to reproduce D. possibly reproduced
不定式作定语
Their little bit of land doesn’t provide enough food to ____.
A. live on B. live C .live in D